Work out sprinkler density requirement instantly with clear inputs, formula shown and shareable results.
Sprinkler design density is the depth of water per minute the system must deliver over the assumed area of operation, set by hazard class: 2.25 mm/min for light hazard up to 10 mm/min or more for high hazard storage. Because one millimetre per minute over one square metre is one litre per minute, flow follows directly, and multiplying by the required duration gives storage.
Design flow
L/min = design density mm/min x area of operation m²
Storage
m³ = flow L/min x duration min / 1000
Preliminary estimate only. Sprinkler system design must be carried out by a qualified fire protection engineer to the applicable standard with full hydraulic calculation.
L/min = design density mm/min x area of operation m². Sprinkler design density is the depth of water per minute the system must deliver over the assumed area of operation, set by hazard class: 2.25 mm/min for light hazard up to 10 mm/min or more for high hazard storage.
It reflects how far a fire is expected to spread before sprinklers control it. Higher hazard occupancies assume a larger area of simultaneous operation as well as a higher density.
This calculator takes 3 inputs: Hazard classification, Assumed area of operation, Required duration. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.