528 calculators across 18 categories. Tap ♡ on any card to save your favorites.
Construction
Slabs, footings, columns - cubic yards + bags.
Grid layout, total feet, lap splice, tie wire count.
Bricks needed + mortar bags for any wall area.
Concrete blocks + mortar for a block wall.
Grout volume for any tile floor or wall.
Sand + portland cement + lime ratios for mortar.
Blocks + cap stones for a retaining wall.
Pavers + sand base for a patio or walkway.
Anchor bolts spacing for a wood sill plate.
Concrete bags per post hole by hole size + post.
Wall weight per linear foot for brick veneer.
Rebar grid spacing + total linear feet for a slab.
Studs, plates, and headers for any wall.
Lumber volume + cost. Hardwood pricing made easy.
Bar, plate, and tube weight in lb and kg.
Boards + screws for any deck size.
Stud depth (3-5/8”, 4”, 6”) + gauge for any deck height. 20 ga to 12 ga options.
Sheets of plywood needed by area + waste.
Floor joist count + lumber needed by span.
Number of rafters needed for any roof length.
Sash weight for double-hung window restoration.
Rough opening dimensions for any door size.
Rise/run, angle, slope %, and rafter length.
Bundles of shingles + underlayment + ridge cap for any roof.
Squares of siding plus J-channel and starter strips.
Linear feet of gutter + downspouts by roof size.
Sheets, screws, mud, and tape for any room.
Gallons for your room. Doors & windows handled.
Tiles + waste % for any floor or wall.
Square yards needed with waste factor and cost.
Rolls needed accounting for pattern repeat.
Order sheet for Hilti firestop: CP 606 / CP 672 spray / FS-One Max / CP 777 deck plugs / mineral wool.
Linear feet of baseboard, crown, or chair rail.
Total linear feet of cabinets from a kitchen layout.
Tubes of caulk needed for any bead size and length.
Screws or nails needed for decking, framing, drywall.
Recommended R-value + how thick that is in fiberglass or foam.
Bags of blown-in or batts to hit a target R-value.
Spray foam coverage at 1 inch + R-value yield.
Dirt volume in cubic yards + dump truck loads.
Room or lot size - rectangle, circle, or triangle.
Cubic yards and tons of crushed stone for any project.
Tons of hot-mix for driveways and parking.
Posts, pickets, rails, and concrete for a wood fence.
Gravel + pipe + filter fabric for a french drain.
Size tank water heater by fixture demand + First Hour Rating (FHR). Showers, tubs, sinks, dishwasher, pipe size.
Gallons of water inside any pipe by diameter + length.
Friction pressure loss in PSI over any pipe run (Hazen-Williams).
Total Fixture Units for a building to size drains + water supply.
Size arrestors by fixture units (PDI standard A-F).
GPM and BTU rating needed for tankless by climate + fixtures.
GPH recovery for any tank water heater (gas or electric).
GPH capacity needed by basement size + water table + lift height.
Required fall over any drain run length.
Minimum thread engagement for NPT fittings (1/8" through 4").
Trench length and area by perc rate + bedrooms.
Elbows, tees, couplings, and crimp rings for a PEX project.
Bags of deck mud for a shower pre-slope or floor pan.
Black iron or CSST size for any BTU load + run length.
Grain capacity needed by household + hardness.
Required cleanout locations per IPC/UPC for any drain layout.
Volts, amps, watts, ohms — solve for any one.
Minimum copper wire AWG for any amperage + distance.
Voltage drop and percentage for any run.
Required service size for a dwelling per NEC standard method.
Right breaker for any continuous or non-continuous load.
NEC Chapter 9 fill limits for any conductor count + size.
kVA rating needed for a load — single or three phase.
Full Load Amps from HP, voltage, and phase (NEC 430).
Available capacity in your existing panel.
Breaker + wire + service room for EV Level 2 install.
Which protection is required by NEC for any room or outlet.
NEC general lighting load by occupancy type.
Volume check for an electrical box (NEC 314.16).
How balanced is your 120/240V panel — find lopsided phases.
Operating cost for any appliance by watts + hours + rate.
Duct dimensions from BTU + CFM by room. Manual D simplified.
Whole-home backup sizing by running watts of all appliances.
Tank gallons by bedrooms and household use.
Cooling BTU/h for any room by sq ft + heat factors.
Whole-home heating + cooling load estimate (simplified).
Round duct diameter for any CFM (residential supply).
Total external static pressure across an HVAC system.
Required CFM by room based on heating + cooling load.
Line set sizes for any mini-split or split AC by tonnage + distance.
ACH for a room from CFM ventilation + volume.
Latent heat from humidity removal during cooling.
COP from BTU output and watts input — and dollar comparison vs gas.
Convert AC efficiency ratings; estimate annual cooling cost.
Condensate drain pipe size by AC tonnage.
BTU input rating from output + AFUE.
Door weight by material, size, insulation - for spring sizing.
IPPT, wire gauge, and spring length from door weight + drum.
HP / torque opener rating from door weight and panel size.
Max travel distance to extinguisher by hazard class (NFPA 10).
Square footage covered per unit by extinguisher rating.
Total units needed by building area and occupancy hazard.
Plan grid layout: spacing + count per floor at a glance.
Coverage per head by type (pendant, upright, sidewall) per NFPA 13.
Design density and area-of-application by NFPA 13 hazard.
Sprinkler discharge Q = K√P - GPM from pressure.
Pipe diameter by GPM - Hazen-Williams friction loss.
Estimated GPM + pressure needed from sprinkler design.
Quick friction loss across a sprinkler riser run.
Nozzle count and spacing for hood + cooking appliances.
Suppression coverage through ductwork by duct size.
Next due date for extinguishers, sprinkler systems, hydrants.
5 / 6 / 12 year retest schedule by cylinder type (NFPA 10).
Annual + 6-year + 12-year service schedule from manufacture date.
What gets inspected weekly / monthly / quarterly / annually.
Tape-measure math - add, subtract, multiply feet-inch-fractions.
IBC / ASCE 7 §13.5.6 compliance checklist + quantities for any suspended ceiling.
Verify any rectangular layout is perfectly square — pools, slabs, decks, sheds. Diagonal check + live diagram + adjustment guide.
Is your roof at risk? Snow weight vs construction type.
Trailer weight vs vehicle towing rating with safety margin.
Stringer + riser + tread, with IRC code check.
Architecture
How much GFA you can build on a lot under your zoning code.
Footprint as a percent of lot area - zoning compliance check.
Hardscape coverage for stormwater + permit compliance.
Front / side / rear setback compliance and buildable envelope.
Required parking by use type and floor area (zoning code).
Golden ratio + ideal room L/W ratios for comfortable spaces.
Usable program area vs total building area - schematic design tool.
Vertical proportion check - cathedral, balanced, oppressive.
Façade glazing percentage and quantity by elevation.
IBC load combos: 1.2D + 1.6L, etc. for design loads.
Max span for 2x lumber and LVL by species and load.
Reference tables - max spans for 2x, built-ups, and LVL across species and loads.
Heavy timber (6x6 to 12x14) - oak, Doug Fir, white pine with connection derates.
L, T, U, trapezoid, and circular pours - cubic yards + cost.
ASCE 7 simplified wind pressure by zone, height, exposure.
Roof snow load by ground snow zone, slope, and exposure.
Glass percentage of exterior wall - IECC energy code check.
Window area to room area - estimate interior daylight.
Sun altitude + azimuth by latitude, date, and time.
Simplified heating + cooling BTU/h by climate zone and envelope.
Sound transmission class for wall assemblies.
Tech & Energy
API cost per request, day, and month for any LLM model.
How many pages, code lines, or tokens fit in any model.
Total cost to train or fine-tune on cloud GPUs (H100, A100, etc).
Hosted fine-tuning cost (OpenAI/Anthropic) for any dataset size.
Full-stack cost: embeddings + vector DB + retrieval + LLM.
GPU server cost vs API cost — when does self-hosting win?
How much you save by trimming a system prompt at scale.
Cost to vectorize any document corpus across providers.
Per-image and bulk cost across DALL-E, Midjourney, SDXL providers.
Voice generation cost across ElevenLabs, OpenAI, Cartesia.
Monthly cost for Cursor, Copilot, Claude Code, or custom agents.
Electricity + carbon for training any model.
kW of panels needed by usage + sun hours + offset target.
Years to ROI for any solar install with tax credits + escalator.
Panels per string by voltage limits and temperature derate.
How much DC oversizing before you clip AC output.
Days of off-grid backup from any battery + critical loads.
Years of life from depth-of-discharge + cycles per year.
Lifetime cost: cash vs loan vs lease vs PPA.
Optimal panel tilt for your latitude + production loss at any pitch.
Production impact of any shading on your array.
Your post-solar electric bill under net metering, net billing, or no compensation.
Savings from charging battery off-peak and discharging on-peak.
Levelized cost of energy from your solar — cents/kWh comparison.
Real range by speed, temperature, and load.
Hours to charge any battery on L1, L2, or DC fast.
Cost per mile across home charging, public L2, DCFC, and Tesla Supercharger.
10-year true cost: EV vs gas including maintenance, fuel, depreciation.
Best charger amp rating for your panel + EV charging needs.
Expected battery capacity loss over years + miles.
Charging stops + total time for any EV road trip.
Total cost of going all-electric (heat pump + EV + solar + battery).
Monthly cost for EC2 instances + reserved vs on-demand savings.
Bandwidth bill across AWS, GCP, Azure, Cloudflare R2, Backblaze.
CDN bill across CloudFront, Cloudflare, Bunny, Fastly.
Storage + IOPS + backups for managed DBs (RDS, Aurora, Supabase, etc).
AWS Lambda, Cloudflare Workers, Vercel Functions per-invocation cost.
Shared, VPS, dedicated, or managed — total cost of ownership.
Optimal storage class (hot/warm/cold/glacier) by access pattern.
Total monthly cost for a managed K8s cluster (EKS, GKE, AKS).
Required QPS or RPM for any traffic level.
Monthly bandwidth from pageviews + page weight.
Daily mining profit by hash rate, electricity, and BTC price.
ETH gas cost in USD by gas price + units used.
Annual yield + compound earnings from staking any crypto.
Dollar-cost average return for any crypto over time.
Estimated capital gains tax owed on crypto sales.
Recommended split between BTC, ETH, alts, stables by risk tolerance.
IL when providing liquidity in any AMM pool.
Vested + unvested tokens by date for cliff/linear schedules.
Education
Reading ease + grade level scores for any text. Used by teachers, the military, and writers.
Stay compliant with state student-to-teacher ratio requirements.
How many students you need at any tuition to cover school costs.
Annual curriculum + supplies cost per student.
Total monthly and annual operating costs for a microschool.
Square footage requirements per student — code compliance check.
Daily, weekly, and chronic absenteeism rates.
Convert grades to weighted GPA with AP/honors bonuses.
Long division shown step-by-step for any two numbers.
Metric ↔ imperial conversion across length, weight, volume, temperature.
Area + perimeter for rectangles, triangles, circles, trapezoids.
Is a number prime? Plus factorization and nearby primes.
Convert decimal numbers to Roman numerals and back.
Compare annual costs across microschool, homeschool, and private school.
Daycare/aftercare savings if your child is in a microschool.
Hours saved per year by picking a closer school.
How much your 529/savings will grow by college years.
Balance any chemical equation automatically with full work shown.
Solve for any one variable: speed, distance, or time.
Density = mass ÷ volume. Solve for any variable.
F = ma. Solve for force, mass, or acceleration.
Maker & Reference
Static compression ratio from bore, stroke, head + deck volumes.
Vehicle speed at any RPM by gear ratio + tire diameter.
Convert 285/70R17 to diameter, width, sidewall, circumference.
Required pump GPH or LPH for any HP target.
Total engine displacement from bore × stroke × number of cylinders.
Tightening torque for any bolt grade + size, dry or lubricated.
Correct drill bit for any tapping thread (UNC, UNF, metric).
Max allowable shear load for any bolt grade + size.
Pilot bit size for any wood screw + wood density.
Weight of fasteners by quantity and size for shipping or material takeoff.
Gauge number to actual thickness in inches + mm.
Which grit for the job? Wood, metal, finishing schedule.
4-band, 5-band, and 6-band color code decoder with visual band picker.
Convert between dBSPL, dBm, dBW, voltage ratios, and power ratios.
Quarter-wave, half-wave, and dipole antenna length at any frequency.
Solve V, I, R, P given any two values.
Decode 3-digit ceramic capacitor codes to µF / nF / pF.
Quick safe current for any AWG copper wire (NEC 310).
Safe working load for any rope by material + diameter.
Percent strength loss for any knot.
Sag at midspan for any cable + load + span.
Haversine formula distance between any two lat/long points. Miles, km, nautical miles, bearing.
Convert magnetic bearing to true bearing and back.
Convert quadrant bearings (N45°E) to azimuth (0-360°) and back.
Slope between two points: percent, degrees, ratio.
Convert sq ft, sq m, hectares to acres and back.
Convert any number to/from scientific notation.
Maximum deflection for simple-supported or cantilever beam.
Solve for any side of a right triangle.
KE = ½mv². Find energy, mass, or velocity.
Count sig figs in a number and apply to math operations.
Density relative to water (1.0). Will it float? How much does it weigh?
Real Estate
True cost: monthly rent vs owning with mortgage, tax benefits, and appreciation.
Max purchase price based on income, debt, down payment, and DTI.
Side-by-side payment + total cost across FHA, VA, USDA, and Conventional.
When PMI drops off based on home equity growth.
Estimated closing costs by purchase price, loan type, and state.
What 0.5% difference in mortgage rate costs over 30 years.
How much DPA you may qualify for by income and state.
Does the upgrade add more to resale than its cost?
Spend money on the lot or interior upgrades?
How much does adding upgrades cost per month on the mortgage?
LVP vs hardwood vs carpet total installed cost per square foot.
Payback period for solar, insulation, tankless water heater, etc.
Estimated close date by phase from groundbreaking.
When money releases at each build phase.
When to lock and what float-down options cost.
True cost: new build vs comparable resale home.
Monthly HOA impact on total affordability and DTI.
Will you qualify for the loan? Front-end and back-end DTI.
How much does going from 680 to 720 save on a mortgage?
Mortgage + taxes + insurance + HOA + maintenance + utilities.
How long to save for a down payment at your current rate.
Annual property tax based on home value and tax rate.
Annual home insurance estimate by region and home value.
Annual cost of commute from new neighborhood including time value.
Compare utility bills between new construction and older homes.
How much salary do you need in a new city to maintain your lifestyle?
What home price equals your current rent payment.
Hosting & Rentals
Suggested nightly rate by bedroom count, location tier, and seasonality.
Optimal discount % for 7+ and 28+ night stays.
Peak vs off-season nightly rates with day-of-week premiums.
Monthly + annual income at any occupancy rate.
Cash-on-cash return and cap rate for any rental property.
Right cleaning fee by bedroom + bathroom count and turnover frequency.
What Airbnb takes vs what you actually pocket after fees.
What you actually take home after Airbnb cut, cleaning, supplies, taxes.
Break down mortgage + utilities + insurance per available night.
Common deductible expenses + estimated tax savings.
Which makes more for your property: Airbnb vs traditional 12-month lease?
How many days per month spent on cleaning, prep, and turnovers.
How many bookings per month to hit your income goal.
Minimum bookings per month to cover all costs.
Revenue impact of 1-night vs 2-night vs weekly minimums.
Toiletries, coffee, linens, paper goods per stay.
Cost per turnover for sheets, towels, and linens.
Yearly supply cost projection based on bookings + tier.
Tree Work
Safe working load by rope diameter, material, and design factor.
Static weight × drop factor = actual peak force on rope and anchor.
Force on the anchor point at any sling/rope angle.
Single, double, triple pulley systems — theoretical and real MA.
How much load a redirect pulley adds to the anchor.
Pendulum arc radius based on rope length and attachment height.
Notch geometry: conventional 45°, Humboldt 70°, or open face 70-90°.
How wide to leave the hinge by tree diameter and species.
Where to place the back cut relative to the notch.
How tree lean affects fall path and side load.
Plunge cut depth and back-strap thickness for controlled release.
Safe lift capacity from boom length, radius, and chart capacity.
Estimated weight of a log section by species, diameter, and length.
Pounds per cubic foot by species, green vs seasoned.
Where a log will balance for crane rigging.
How sling angle multiplies the force on each leg.
Total tree weight from DBH, height, and species.
Estimated weight of a limb by diameter, length, and foliage state.
Estimated wind force on a tree or canopy at any wind speed.
Safe working height of a spar after topping.
Weight × drop height = impact force on ground or stop point.
How far a section can travel when it hits the ground.
45° escape path from the stump based on tree height.
Whether your bar is long enough for the cut.
Helmet, harness, lanyard ratings vs forces involved.
Home
Aquarium volume in gallons + liters from tank size. Plus filter GPH, heater wattage, weight loaded, fish stocking.
Daily cup amount by weight, age, activity level, and food type.
BTU recommendation for any room.
What that appliance costs you per month.
Meat, sides, drinks, ice for your cookout.
What your water heater costs to run per year.
Annual energy cost for any appliance by watts + hours.
Lifetime savings from switching to LED bulbs.
How long a propane tank lasts at your usage rate.
Gallons of heating oil per winter by house size.
BTU output by cord type and burn rate.
When to replace HVAC filter by MERV rating + house size.
Pounds of salt per month by water hardness + people.
Monthly savings from a residential solar install.
How long a home battery powers your essentials.
Pints/day capacity needed by room size + humidity.
Gallons/day needed for whole-home or single room.
PEX loops + length for radiant floor heating.
BTU and number of heads for ductless HVAC.
CFM rating needed for attic ventilation.
Pool
Yard grading around the pool - fall percent, drainage slope.
How close can the pool be to fence, house, or property line.
Dig + haul cost per cubic yard, including trucks and disposal.
How long to fill a pool at any GPM from hose, truck, or hydrant.
Structural load from water on decking, slabs, or tanks.
Daily water loss to evaporation by climate - inches and gallons.
Build cost broken down per gallon - quick sizing for bids.
Concrete deck area around the pool minus the pool footprint.
Linear feet of coping for any pool perimeter.
Cubic yards of gunite for shell + waste factor.
Hours to cycle full pool volume at your pump GPM.
Pipe diameter vs GPM - velocity, head loss, recommended size.
Amps and breaker size for pump + heater + lights combined.
Gallons in your pool - rectangle, round, or oval.
Chlorine, pH, and alkalinity doses for your pool.
Pounds of pool salt to hit your target PPM.
How much shock to break point chlorination by volume.
CYA dose to hit target ppm - plus dilution to lower it.
Health
Devine, Robinson, Miller, and Hamwi ideal weight formulas.
WHR with health risk categories by sex.
WHtR risk assessment in seconds.
LBM via Boer, James, Hume formulas.
Total Daily Energy Expenditure with activity multipliers.
How long to lose X pounds at a given deficit.
Calorie surplus + protein needs for muscle gain.
Daily protein target by goal (cut, maintain, bulk).
Hours to fast + eating window for popular IF protocols.
Pace, time, distance - with race preset buttons.
Max heart rate + 5 training zones.
MET-based calorie burn for 30+ activities.
Convert step count to miles using your height.
Calories burned walking by distance + pace + weight.
Calories burned by stroke type and time in pool.
Calories burned biking by speed, terrain, and weight.
Pace progression to finish a 5K in your goal time.
Estimate 1RM from rep test + training percentages.
Weekly tonnage + per-muscle group breakdown.
How your pushup count compares for your age and sex.
Body Mass Index in metric or imperial.
BMR + TDEE using Mifflin-St Jeor.
Protein, carbs, fat grams by goal and split.
US Navy tape method, with category ranges.
Daily water target by weight, activity, climate.
Bedtimes that align with 90-min sleep cycles.
Daily formula ounces by weight and age.
Your dog's age in human years, size-adjusted.
Optimal wake time + bedtime based on 90-minute sleep cycles. Wake up rested, not groggy.
Finance
Real rate factoring health insurance, retirement, vacation, and PTO.
Is it actually worth the hours? Profit per hour invested.
Year-by-year break-even. When does buying beat renting?
When repurchasing is better than getting your money back.
Future value with periodic contributions and compounding.
Return on investment percentage and annualized return.
Units to sell to cover fixed + variable costs.
Gross, operating, and net margin from revenue and costs.
Convert markup ↔ margin and price products correctly.
What hourly rate to charge to hit a target income.
Monthly payment, total interest, and amortization.
Take-home pay after federal, state, FICA, and benefits.
Time to debt freedom under each method with cost comparison.
How long or how much per month to reach a target.
Assets minus liabilities - personal balance sheet.
Cash flow, cap rate, and cash-on-cash for any rental.
Full burdened cost including taxes, benefits, overhead.
Lease vs buy break-even for a new car.
True 10-year cost of any car: depreciation + fuel + maintenance + insurance.
Max car payment by your income (20/4/10 rule).
Convert salary to hourly + back, with PTO factored in.
Did your raise actually keep up with inflation?
Where you should be at 30, 40, 50, 60 - and where you are.
FIRE number + safe withdrawal rate.
When can you retire? Years to FI based on savings rate.
62 vs 67 vs 70 - lifetime payout comparison.
Take the lump or the monthly check? Run the math.
Avalanche vs minimum payment savings.
How much youre leaving on the table without max match.
Allocate income to needs/wants/savings.
Target emergency fund by monthly expenses + risk tolerance.
How long minimum payments take + total interest paid.
Lifestyle
True cost of all your subscriptions over 1, 5, and 10 years.
Does cutting cable actually save you money? Run the real numbers.
Break-even year for buying electric. Charging vs gas + maintenance.
True cost per meal including grocery, prep time, and waste.
Real annual cost by lines, data tier, and accessories.
What does going to the office actually cost you per year?
True multi-year cost of a car / phone / appliance - incl. depreciation.
Daily, monthly, and lifetime food cost by pet weight + brand.
The 3-month rule deconstructed - what you can actually afford.
Total wedding cost broken down per head - plus how to trim it.
Total cost of a road trip: gas + lodging + food.
Miles remaining on tires + when to replace.
Annual oil change cost by service interval.
Cost per mile and per full charge for any EV.
Annual cost of gas mower vs electric mower.
Daily parking vs monthly garage break-even.
Total yearly cost of your daily commute.
One-time cost of a real home office setup.
What unpaid time off costs you per day/year.
Allocate a wedding budget across all categories using industry-standard percentages.
Food & Kitchen
What you actually end up with after trim + cook loss for any cut.
True cost per pound after yield loss — what brisket REALLY costs you.
Is the bulk buy actually worth it after yield + freezer space + your time?
Is Prime really worth the premium over Choice for your use case?
Weight × temp × cut → estimated finish time.
How long to rest by weight + cut for juicy slices.
Work backwards from your serve time to know when to start the cook.
Safe thawing time by weight, in fridge vs cold water vs counter.
Estimated stall temp + duration for any cut of meat.
How much wood, charcoal, or pellets for X hours at X temp.
How many lb to buy for a crowd, AFTER yield loss.
How much pulled pork comes off a bone-in shoulder.
Salt-to-water ratio by volume — for any brine batch size.
Curing salt (sodium nitrite) by meat weight — safety critical.
How much rub by surface area or weight of any cut.
How many briskets, ribs, butts, or chickens fit on your smoker.
Scale a pasta salad recipe for any number of guests. 6 styles + optional protein.
Swap butter ↔ oil ↔ shortening ↔ applesauce with ratios.
Edible portion percent (EP%) after trim and waste.
Cost per plate from recipe + EP% - menu pricing math.
How much mise en place by covers and portion size.
Safe thawing time by weight + method (fridge, cold water, microwave).
Cook time for any turkey size at any oven temp.
Brisket smoke time by weight + target temp.
Salt + sugar + water ratios for any brine.
Marinade volume + balance for any meat quantity.
Chip quantity by smoker type and cook duration.
How many fries before you change deep-fryer oil.
Baker percentage math for any sourdough. Flour, water, starter, salt + timing by kitchen temp.
Coffee-to-water ratio for any brew method.
Convert a recipe between pan sizes.
Baking conversions for 23 ingredients.
Scale any ingredient list up or down.
Baker's % math for any pizza style.
Convert F to C, plus convection/fan adjustments.
Recipe adjustments by elevation.
Bakers percent hydration for any flour + water amount.
Alcohol By Volume from OG and FG readings.
Distribute tip pool to busser, bar, runner - percentage based.
Pour cost % from cost-per-bottle and selling price.
Pours per bottle by size and shot size.
Pints / pours per keg by size - 1⁄2 barrel, 1⁄6 barrel, sixtel.
Margin and profit per drink across menu items.
Scale a single-serve recipe to a batch by number of servings.
Blood alcohol estimate by weight, drinks, time, sex (Widmark).
Plan a BBQ for any guest count: proteins, sides, drinks, cups, napkins, ice — all sized to your crowd.
Plate counts and food weights by event size.
Serving sizes per guest for buffet-style events.
Dessert portions and total servings for any event.
Interactive board builder: guest count + style + checkbox items → shopping list with quantities + costs.
Math
Suggested tips for restaurants, salons, hotels, rideshare, food delivery, and more.
Business days between dates, or add N days to a date.
Exact age in years, months, days, and seconds.
Add or subtract hours, minutes, and seconds.
Days, weeks, months between any two dates.
Exact age gap between two people.
Solve hypotenuse or any leg of a right triangle.
Solve ax2 + bx + c. Real and complex roots.
Monthly payment + total interest with tax and trade-in.
Percent of, what %, percent change - all in one.
Add, subtract, multiply, divide fractions.
Bill + tip % + split between people.
Add tax or strip it back out of any total.
Monthly payment + total interest for any loan.
PITI: principal, interest, tax, insurance, PMI, HOA.
Simple or compound, with monthly contributions.
Trip cost + monthly commute cost.
Weighted GPA with as many courses as you want.
Gas cost for any trip by miles + MPG + price.
Track and average your MPG across fill-ups.
Multiple discounts: best stacking strategy.
Total bill with tax + tip + split between people.
Unit price for grocery comparison shopping.
Reduce fractions to lowest terms.
Convert decimals to fractions and back.
Hours and minutes to decimal hours for timesheets.
Garden
C:N ratio for hot compost using browns + greens.
NPK rate, lawn size → pounds of fertilizer.
Cubic yards of mulch for any garden bed.
Soil for raised beds and planters, with presets.
How many plants fit in your bed at any spacing.
Pounds of grass seed by lawn size and type.
Pounds of N per 1000 sqft from any NPK ratio fertilizer.
Trading Cards
Is grading worth it? Fees vs raw-to-graded value bump.
Total grading cost across tiers - fees, shipping, insurance.
eBay/PWCC/COMC fees - what your card has to sell for.
Fair-share box break pricing - by team, division, or random.
Expected hits per box from stated 1:N odds.
Was your box above or below expected value?
USPS PWE / Ground Advantage / Priority - pick the cheapest.
Bulk collection value with up/down trend per card.
When does a small box beat a bubble mailer? Find the cutoff.
How many cards fit in your binder by sleeve thickness.
How many slabs, toploaders, or sleeves fit in a box or briefcase.
Evenly space frames or slabs on a wall - exact center marks.
USPS GXG, Priority Intl, and First-Class Intl rates for cards.
Photography
Resize images while preserving aspect ratio.
Is your image big enough to print sharp?
DoF, hyperfocal, near + far focus limits.