Calculator Inputs
Use the responsive input grid below. Results appear above this form after submission.
Example Data Table
These examples are illustrative planning scenarios only.
| Project | Area (m²) | Density (L/min/m²) | Hose (L/min) | Duration (min) | Design Flow (L/min) | Storage (L) |
|---|---|---|---|---|---|---|
| Small Workshop | 900 | 8.10 | 500 | 90 | 10,063.35 | 996,271.65 |
| Warehouse Block A | 1,800 | 10.20 | 950 | 120 | 31,349.34 | 4,138,112.88 |
| Processing Hall | 2,400 | 12.20 | 1,500 | 180 | 57,681.84 | 11,421,003.84 |
Formula Used
This calculator uses a configurable planning model for construction fire water demand.
Use these results for early sizing, option comparison, and budget discussions. Final design should follow the governing fire protection basis, authority requirements, and the project’s approved strategy.
How to Use This Calculator
- Enter the project name and select the hazard class.
- Input the protected area and choose the correct area unit.
- Enter the water density and select its unit.
- Add hose stream allowance and design duration.
- Set the hazard, construction, exposure, and communication factors.
- Add safety margin and storage reserve percentages.
- Enter available supply flow and available storage.
- Click the calculate button to see design flow, storage demand, margins, graph, and export options.
Frequently Asked Questions
1) What does this calculator estimate?
It estimates planning-level fire water demand, required storage volume, flow conversions, and supply adequacy using project area, density, duration, hose allowance, and adjustment factors.
2) Is this suitable for final code compliance?
No. It is best for early design, cost studies, and option screening. Final design must be verified against the project fire strategy, local regulations, insurer guidance, and approved protection criteria.
3) Why are there multiple adjustment factors?
Real projects differ in hazard severity, building construction, nearby exposures, and operational complexity. Separate factors let you model those influences instead of relying on a single base flow only.
4) What is hose stream allowance?
It is the extra flow reserved for manual firefighting support, such as hydrants or hoses, in addition to the calculated sprinkler or process demand.
5) Why does the graph use cumulative demand?
Cumulative demand shows how quickly stored water is consumed over the design duration. It helps you see when available storage becomes insufficient during an incident.
6) Can I use square feet and GPM per square foot?
Yes. The calculator converts square feet to square meters and GPM per square foot to liters per minute per square meter before applying the demand equations.
7) What do the recommended pump and tank values mean?
They are practical rounded-up targets. The pump includes a small operational allowance, and the tank size includes extra headroom for more realistic procurement planning.
8) When should I increase the safety margin?
Increase it when design uncertainty is high, future expansion is expected, water supply is unreliable, or the project still lacks confirmed fire protection criteria.