Fire Extinguisher Quantity Calculator

Not a fixed number. The Regulatory Reform (Fire Safety) Order 2005 requires "appropriate fire-fighting equipment" for non-domestic premises in England and Wales, but the exact number, type and siting must be determined by a fire risk assessment, not a single legal figure. BS 5306-8's guidance - one 13A Class A extinguisher per 200 m², minimum 2 per floor - is the widely used technical benchmark most assessments and suppliers work from, which is what this calculator applies.

BS 5306-8, "Selection and installation of portable fire extinguishers", the British Standard most UK fire-safety guidance and suppliers cite for extinguisher provision. A 13A-rated water or foam extinguisher is judged able to cover roughly 200 m² of ordinary Class A combustible risk (paper, wood, textiles, general office and retail materials).

BS 5306-8 guidance sets a 2-per-floor minimum regardless of area, so a single small office or shop unit still needs 2, not 1 - partly for redundancy (a spent or faulty extinguisher shouldn't leave a floor with none) and partly so a fire in one part of a small floor doesn't leave someone needing to cross the fire to reach the only extinguisher.

CO2 (carbon dioxide) extinguishers are the standard choice for fires involving live electrical equipment, because they leave no residue and don't conduct electricity back through the extinguisher onto the user - unlike water or foam extinguishers, which are not safe to use on live electrics. If your premises has server equipment, electrical panels or similar risk, guidance typically adds at least one CO2 extinguisher per floor alongside the Class A provision.

A wet chemical (Class F) extinguisher, designed for cooking oil and fat fires, plus a fire blanket for smaller pan fires - a standard water, foam or CO2 extinguisher is not appropriate for a deep-fat fryer fire and can make it worse. This calculator adds one of each when you flag a commercial kitchen with deep-fat frying.

Not automatically - it adds one wet chemical extinguisher and one fire blanket regardless of floor count, assuming a single kitchen area. If you have more than one separate kitchen, add one more wet chemical extinguisher and one more fire blanket per additional kitchen to the tool's total by hand.

Only above the 200 m² threshold per extinguisher, and only once you cross into needing a 3rd, 4th (and so on) unit - the minimum of 2 per floor means a 50 m² room and a 199 m² room both need exactly 2 Class A extinguishers under this guidance; the count only increases once a floor passes 200 m², 400 m², 600 m² and so on.

That's a common and reasonable outcome, especially in premises that have grown or changed use over time - the tool shows this as a surplus rather than treating it as wrong. Extra Class A coverage is rarely a problem, but if your surplus is concentrated in the wrong type it's still worth checking the mix against your risk assessment, not just the total count.

No - the "extinguishers you currently have" field is a single total count compared against the total requirement, not broken down by type. If your current stock is mostly one type and light on another, the total comparison alone can hide a type-specific shortfall - check the breakdown table's type-by-type figures against what you actually hold, not just the overall total.

This calculator doesn't cover servicing schedules, but UK guidance generally recommends an annual service by a competent person (often BAFE-registered), alongside monthly visual checks by premises staff for damage, tampering or a low pressure gauge reading. Extinguishers are typically replaced or recharged after use, and stored-pressure water and foam types are commonly discharge-tested and refilled around every 5 years per manufacturer guidance.

No - fire extinguishers are firefighting equipment for tackling a small fire at its early stage; fire detection and alarm systems are a separate requirement under the same Fire Safety Order, sized differently (by building layout and evacuation strategy, not floor area per extinguisher). This calculator only covers portable extinguisher provision.

The "responsible person" for the premises - typically the employer, building owner, or whoever has control of the premises - under the Regulatory Reform (Fire Safety) Order 2005. That person must ensure a suitable and sufficient fire risk assessment is carried out and kept up to date, which this calculator can inform but not replace.

This tool is built for non-domestic premises risk (offices, shops, warehouses) covered by the Fire Safety Order. Blocks of flats and other residential buildings sit under different, more specific fire safety guidance, so use guidance specific to residential buildings instead of this tool's figures for that use case.