Work out sprinkler system flow instantly with clear inputs, formula shown and shareable results.
Sprinkler system demand is design density multiplied by the assumed area of operation, since one millimetre per minute over one square metre is one litre per minute. Individual sprinkler discharge follows the orifice relation q = K sqrt(p), so dividing total flow by sprinkler discharge shows how many heads the design implies.
System flow
L/min = design density mm/min x area of operation m²
Sprinkler discharge
q = K x sqrt(pressure in bar)
Preliminary estimate only. Sprinkler system design must be carried out by a qualified fire protection engineer to the applicable standard and hydraulically calculated node by node.
L/min = design density mm/min x area of operation m². Sprinkler system demand is design density multiplied by the assumed area of operation, since one millimetre per minute over one square metre is one litre per minute.
Not every sprinkler in a building operates in a fire. Standards define a design area, typically 72-260 square metres by hazard class, that the water supply must cover simultaneously.
This calculator takes 4 inputs: Design density, Assumed area of operation, Sprinkler K factor, Pressure at the sprinkler. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.