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NFPA 10
Validated against the standard.
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$2.99 Pro
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How it works
Enter your values
Type in your inputs — the app fills code tables and constants for you, so there's nothing to look up.
Get a code-checked result
Instant answer with a clear PASS / FAIL and the exact NFPA 10 reference behind every number.
Save & export
Keep a history of calculations and export a clean PDF report to share or attach to a permit (Pro).
What this calculator does
Portable fire extinguishers have to be the right type and close enough to reach. This app applies NFPA 10 to determine the minimum extinguisher rating and the maximum travel distance for a space based on its hazard class.
The NFPA 10 rules
- Class A (ordinary combustibles) — maximum travel distance to an extinguisher is 75 ft, with minimum ratings by hazard and floor area.
- Class B (flammable liquids) — travel distance of 30 or 50 ft depending on hazard and extinguisher rating.
- Class K, C, D — kitchen, electrical, and combustible-metal hazards have their own placement rules.
Worked example
For a light-hazard office, NFPA 10 caps Class A travel distance at 75 ft, so extinguishers are spaced so no point on the floor is more than 75 ft from one — the app reports the count and spacing for the area.
Related calculators
Classify the space with the hazard classification calculator and see related rules in the NFPA reference.
Fire extinguisher FAQ
What is the maximum travel distance for Class A?
NFPA 10 limits travel distance to a Class A extinguisher to 75 ft. Class B is 30 or 50 ft depending on the hazard and the extinguisher's rating.
How is the rating chosen?
The minimum A or B rating depends on the hazard level and the floor area protected, which sets both the size and the number of extinguishers.
Does it cover kitchen (Class K)?
Yes, along with Class C electrical and Class D metal hazards, each of which has its own placement requirements in NFPA 10.
Does it work offline?
Yes, it runs 100% offline with no account. Free with rewarded ads; a one-time $2.99 Pro unlock adds PDF export and saved history.
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