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Fire Water Storage Calculator

Work out fire water storage instantly with clear inputs, formula shown and shareable results.

About Fire Water Storage Calculator

Fire water storage is the combined design flow of the systems assumed to operate together, sustained for the required duration. Codes specify which systems are additive: sprinklers and hydrants are usually combined, hose reels are added, and the duration ranges from thirty minutes for light hazard to two hours or more for high hazard storage.

Formula

Storage volume

Litres = (sprinkler flow + hydrant flow + hose reel flow) x required duration in minutes

Worked example

With the default values below, Fire Water Storage Calculator returns Fire water storage required of 120.24. Change any input above and every figure here is recalculated in your browser.

Inputs used

Sprinkler design flowminimum 0 L/min
1,080 L/min
Hydrant design flowminimum 0 L/min
900 L/min
Hose reel flowminimum 0 L/min
24 L/min
Required durationminimum 1 min
60 min

Results

Fire water storage required
120.24 m³
Combined design flow
2,004 L/min
Storage in litres
120,240 L
Duration provided
1.00 h

Step by step

  1. 1Values used
  2. 2Storage volume
  3. 3Fire water storage required= 120.24 m³
  4. 4Combined design flow= 2,004 L/min
  5. 5Storage in litres= 120,240 L
  6. 6Duration provided= 1.00 h

Assumptions and limits

  • The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
  • Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
  • Preliminary estimate only. Fire water demand and storage must be determined by a qualified fire protection engineer to the applicable code.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Preliminary estimate only. Fire water demand and storage must be determined by a qualified fire protection engineer to the applicable code.

Frequently Asked Questions

How is the Fire Water Storage figure worked out?

Litres = (sprinkler flow + hydrant flow + hose reel flow) x required duration in minutes. Fire water storage is the combined design flow of the systems assumed to operate together, sustained for the required duration.

Must all systems be assumed to operate at once?

That is the conservative and commonly required assumption. Some codes allow the hydrant demand to be reduced where sprinklers are installed, on the basis that sprinklers control the fire before manual attack begins.

What values do I need to enter?

This calculator takes 4 inputs: Sprinkler design flow, Hydrant design flow, Hose reel flow, Required duration. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.

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