Fire extinguisher calculator: how many fire extinguishers your floor needs under IS 2190
Updated By Flamekite Editorial DeskFacts checked against official sources on
Free fire extinguisher calculator: enter floor area, floors and hazard class to get the number, rating and walking distance under IS 2190:2024 clause 7.
Quick answer
Under IS 2190:2024 clause 7.2, one extinguisher may cover at most 300 m² of floor in a light hazard, 150 m² in a moderate hazard and 100 m² in a high hazard, with at least two on every floor of 100 m² or more. Divide the floor area by that figure, round up, and never go below two.
Each unit needs a Class A rating of at least 2A, 3A or 4A, and no point of the floor may be more than 20 m (15 m in a high hazard) from one. Flammable liquids, gas, live electrics, cooking oil and metals each add their own type, which the calculator lists with the clause.
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Fire extinguisher requirement per area under IS 2190:2024
| Option | Class A minimum rating | Class A maximum travel | Maximum floor area per extinguisher | Class B and C minimum rating | Class B and C maximum travel | Source |
|---|---|---|---|---|---|---|
| Light hazard | 2A | 20 m | 300 m² | 55B | 15 m | IS 2190:2024 |
| Moderate hazard | 3A | 20 m | 150 m² | 144B | 15 m | IS 2190:2024 |
| High hazard | 4A | 15 m | 100 m² | 233B | 15 m | IS 2190:2024 |
Fire extinguisher requirement calculation in 5 steps
Pick the hazard class
Annex B of IS 2190:2024 gives example criteria, not hard rules: light hazard is under 15 occupants, under 300 m² and up to 15 m high; high hazard is over 250 occupants, over 3,000 m² or over 15 m; moderate is in between.
Divide each floor by the area per unit
300 m² a unit for light, 150 m² for moderate and 100 m² for high hazard (cl. 7.2). Round up.
Apply the two-per-floor minimum
Every floor of 100 m² or more carries at least two units; a floor under 100 m² may have one (cl. 7.2.2).
Check the walking distance
No point may be more than 20 m from a Class A unit, or 15 m in a high hazard. On a cut-up plan this can need more units than the area count.
Add units for the special risks
Class B and C units of at least 55B, 144B or 233B within 15 m of liquids and gases; units marked for energised equipment near panels; a Class F unit within 10 m of a fryer; a unit marked for the metal for Class D (cl. 6, 7.3 to 7.7).
Which extinguisher type for which fire class
Clause 6 matches the type to the fire class first, and clause 7 then sizes it. These are the suitability lines IS 15683:2018 sets out.
| Class A (solids) | Class B (liquids) | Class C (gases) | Class F (cooking oil) | Live electrical | |
|---|---|---|---|---|---|
| Water based | Yes, A rating | No | No | No | No |
| Foam | As rated | As rated, B rating | By B rating | No | No |
| ABC powder | Yes, A rating | As rated | By B rating | No | If marked suitable |
| Carbon dioxide | No A rating | As rated | By B rating | No | If marked suitable, no metal horn |
| Clean agent | As rated | As rated | By B rating | No | If marked suitable |
| Water mist | As rated | As rated | By B rating | Only if F rated | If marked suitable |
Class D metals need a unit marked for that metal. Class F units are sized by the cooking area: 5F up to 0.03 m², 15F up to 0.05 m², 25F up to 0.08 m², 75F up to 0.25 m² (cl. 7.7). IS 15683:2018
How many fire extinguishers are required: 6 worked floors
Flamekite’s working from the official rules; no government publishes this figure.
Flamekite's arithmetic from the clause 7 limits. The number is the larger of the area count and what the walking distance needs.
Case 1
A small shop
One floor of 80 m², light hazard
What applies Under 100 m², so one 2A unit is the minimum (cl. 7.2.2). Two is the safer plan where the floor has two exits. IS 2190:2024
Case 2
An open-plan office floor
One floor of 1,200 m², light hazard
What applies 1,200 divided by 300 is 4 units of at least 2A, no point more than 20 m from one. IS 2190:2024
Case 3
A 5-floor office building
5 floors of 450 m², light hazard
What applies 450 divided by 300 is 1.5, rounded up to 2 per floor: 10 units of at least 2A in all. IS 2190:2024
Case 4
A workshop with paint and solvents
600 m², moderate hazard, flammable liquids
What applies 600 divided by 150 is 4 units of at least 3A, plus Class B units of at least 144B within 15 m of the liquids. IS 2190:2024
Case 5
A storeroom
400 m², high hazard
What applies 400 divided by 100 is 4 units of at least 4A, none more than 15 m away, with 233B units for any flammable liquid. IS 2190:2024
Case 6
A restaurant fryer
Cooking area of 0.04 m²
What applies 15F covers up to 0.05 m², so one 15F unit within 10 m, on top of the Class A units for the dining floor. IS 2190:2024
Where the count needs a closer look
The area count is the floor of the requirement, not the answer for every plan.
If Walls and corridors break up the floor
Walk the plan: if any point is more than 20 m (15 m in a high hazard) from a unit, add one, whatever the area count says. IS 2190:2024
If Adding up small Class B units
Lower-rated units may not be added together to reach the rating, except up to 3 AFFF units whose ratings sum to it (cl. 7.3.2). IS 2190:2024
If A metal fire risk
Class D units are sized by the metal and its particle size, not by area. Ask us with the metal and the quantity. IS 2190:2024
If Your state or NOC asks for more
IS 2190 sets minimums (cl. 1.3). A state rule or the fire officer's NOC conditions can ask for more; Mizoram's draft rule of one per 200 m² is not yet in force. IS 2190:2024
If Buckets in place of extinguishers
The standard does not recommend fire buckets as a replacement, though they may be added on top. IS 2190:2024
Questions about fire extinguisher calculation
How do I calculate how many fire extinguishers a floor needs?
How many fire extinguishers per square foot are required?
What rating should each fire extinguisher have?
Does a small room under 100 m² need two extinguishers?
Which extinguisher goes near an electrical panel?
Keep reading
- IS 2190:2024The code of practice, clause by clause.
- Fire extinguishersTypes, classes, colour codes and ratings.
- Fire NOC for restaurantsKitchen and Class F duties.
- Fire NOC for hospitalsExtinguisher duties in a high hazard occupancy.
- Fire NOC for factoriesHazard classes in industry.
- Fire NOC for shopsWhat a small shop needs.
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Sources
Each source was opened and read on the date shown. How Flamekite checks its sources
- Bureau of Indian Standards: IS 2190:2024, Selection, Installation and Maintenance of First-Aid Fire Extinguishers (Portable and Mobile), Code of Practice, fifth revision (free download after registration) (opens in a new tab)
- Bureau of Indian Standards: IS 15683:2018, Portable Fire Extinguishers, Performance and Construction, Specification (second revision) (free download after registration) (opens in a new tab)