Hydrant Flow Calculator
Enter the field flow-test readings — static, residual, pitot. This tool computes the tested flow per NFPA 291 pitot formula and projects the available flow at 20 psi residual for hydraulic design.
Educational estimator. Field flow tests must follow NFPA 291 methodology under safe conditions. This tool computes math on the numbers you enter — it does not verify test-method correctness. Hydraulic design must be sealed by a licensed engineer or NICET III. Cite: NFPA 291-2022.
Flow test results
Test flow (Q at pitot)—
Pressure drop (static − residual)—
Available flow at 20 psi residual
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Show the math
Code cited: NFPA 291-2022 §4.10 (pitot formula), §4.11 (Hazen-Williams flow projection). The Q₂₀ figure is the design-basis flow used for sprinkler hydraulic calculations.