Construction
Gas Pipe Sizing Calculator
Natural gas pipe sizing from NFPA 54 / IFGC tables. Wrong size = appliances starve at peak load.
Pipe size
—
- Capacity (BTU/hr)
- —
- CFH (1,000 BTU/cuft)
- —
- CSST option
- —
FAQ
Why 0.5" WC pressure drop? +
Standard for residential. Anything more starves appliances at full fire (water heater + furnace + range running together).
CSST sizes smaller? +
Yes, CSST has smoother bore. Verify with manufacturer tables — sizes are not directly interchangeable with black iron.