Fire Suppression
Extinguisher Coverage Area
Pick the extinguisher rating + hazard class. We return the max area one unit can protect per NFPA 10 tables.
NFPA 10 Table 6.2.1.1 (Class A)
| Rating | Light hazard | Ordinary | Extra hazard |
|---|---|---|---|
| 1-A | 3,000 sf | — | — |
| 2-A | 6,000 sf | 3,000 sf | — |
| 3-A | 9,000 sf | 4,500 sf | 3,000 sf |
| 4-A | 11,250 sf | 6,000 sf | 4,000 sf |
| 6-A | 11,250 sf | 9,000 sf | 6,000 sf |
| 10-A | 11,250 sf | 11,250 sf | 10,000 sf |
| 20-A | 11,250 sf | 11,250 sf | 11,250 sf |
| 40-A | 11,250 sf | 11,250 sf | 11,250 sf |
Maximum protected area is capped at 11,250 sf per extinguisher regardless of rating. Travel distance still controls (max 75 ft for Class A).
FAQ
Why two different limits? +
The coverage table is one constraint. The 75 ft max travel distance is another. Both must be satisfied — whichever requires more extinguishers wins.
What about Class B? +
Class B uses spacing (50 ft light, 30 ft extra), not area. Rating controls hazard intensity, not area covered.