Kerova

Calculator · Fire extinguishers · BS 5306-8

Fire extinguisher numbers calculator

Enter the floor area of a storey and choose the Class A rating of the extinguisher you plan to use. You get the minimum number for ordinary fires in solid materials, with the working.

Your figures

m²

The rating is printed on the extinguisher, for example 13A.

Result

Enter the floor area to see the result.

Working

total Class A rating = the higher of 26A and 0.065 × floor area (m²)

  • A storey of 50 m² or less needs at least one extinguisher, with a total Class A rating of at least 26A.
  • A larger storey needs at least two, totalling at least 26A up to 400 m². Above 400 m², the total is 0.065 × the floor area in m², which is about 13A for every 200 m².
  • The travel distance to the nearest extinguisher is no more than 30 m for Class A, and 10 m for Class B and Class F risks. Take 5 m off for each door someone has to open.

Source: BS 5306-8:2023, as set out in an industry technical memo on the standard (Tech Memo 96) and in supplier guides. This covers Class A only.

Special risks need their own extinguishers: electrical equipment, flammable liquids and cooking. See the extinguisher type guide.

For guidance only. Always check against the current edition of the standard and the manufacturer's data.

Built by the engineer behind Kerova, certificate software for fire and security firms.