Fire Extinguisher Spacing Calculator - NFPA 10 Reference Tool
Estimate fire-extinguisher spacing using room dimensions and hazard inputs. Use the result as a starting point and confirm the adopted requirements and AHJ direction.
Calculator
Results
Max Travel Distance
75 ft
Floor Area per Extinguisher
3,000 sq ft
Minimum Extinguishers Required
2
Rating Required
2-A
Results based on NFPA 10 (2022 edition) Table 6.2.1.1. Always verify with your local AHJ.
Understanding NFPA 10 spacing requirements
NFPA 10 Section 6.2 sets specific requirements for how far apart fire extinguishers can be placed - and how far someone can travel to reach one. These requirements vary by hazard classification.
Travel distance limits
- Light Hazard: 75 feet maximum travel distance to nearest extinguisher
- Ordinary Hazard: 75 feet maximum travel distance
- Extra Hazard: 50 feet maximum travel distance (shorter because fires grow faster)
Coverage area per extinguisher
NFPA 10 also specifies the maximum floor area a single extinguisher can cover, based on its rating:
- Light Hazard: 3,000 sq ft per 2-A rated extinguisher
- Ordinary Hazard: 1,500 sq ft per 2-A rated extinguisher
- Extra Hazard: 1,000 sq ft per 4-A rated extinguisher
Your local fire marshal or AHJ may have additional requirements. Always confirm during pre-construction meetings or plan reviews.
Use the free calculator
- Estimate spacing from room dimensions and hazard inputs
- Supports Light, Ordinary, and Extra hazard classifications
- Enter room dimensions for automatic travel distance calculation
- Get extinguisher count, type, and placement recommendations
- Works on mobile - calculate on site during inspections
Results are a planning aid. Verify the final layout with the adopted requirements and local AHJ.
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FireInspected organizes service documentation; it does not replace adopted requirements, manufacturer instructions, qualified service work, or AHJ direction.