Fire Hose Friction Loss Calculator
FL = C·Q²·L — the fireground friction formula with standard hose coefficients.
Kept in US units to match pump-operator training. 200 ft of 1¾" at 150 gpm loses ~70 psi — why long small-bore stretches starve nozzles.
Formula
Fire Hose Friction Loss Calculator is a free fire hose friction loss for pump engineers, plumbers and plant designers — instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.
About Fire Hose Friction Loss Calculator
FL = C·Q²·L — the fireground friction formula with standard hose coefficients. The calculation implements FL = C·(Q/100)²·(L/100) (US units, NFPA convention) (IFSTA Pumping Apparatus Driver/Operator Handbook). Kept in US units to match pump-operator training. 200 ft of 1¾" at 150 gpm loses ~70 psi — why long small-bore stretches starve nozzles.
How to use Fire Hose Friction Loss Calculator
- 1Enter Hose coefficient C (1¾" = 15.5 · 2½" = 2 · 5" supply = 0.08).
- 2Enter Flow in gpm.
- 3Enter Hose length in ft.
- 4Read Friction loss instantly — no submit button needed.
Why use Fire Hose Friction Loss Calculator?
- ✓Implements the standard formula — FL = C·(Q/100)²·(L/100) (US units, NFPA convention)
- ✓Reference cited on-page: IFSTA Pumping Apparatus Driver/Operator Handbook
- ✓Live worked example: the substitution recomputes from your numbers
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the Fire Hose Friction Loss Calculator use?+
It computes FL = C·(Q/100)²·(L/100) (US units, NFPA convention), per IFSTA Pumping Apparatus Driver/Operator Handbook. The formula is displayed under the result along with a worked example substituted with your own inputs.
What should I keep in mind when using this calculator?+
Kept in US units to match pump-operator training. 200 ft of 1¾" at 150 gpm loses ~70 psi — why long small-bore stretches starve nozzles.
Can I use this for pump selection?+
Use it to establish the duty (flow, head, NPSH, power) and then pick a pump whose curve passes through that point near best efficiency. The tool gives you the engineering numbers a supplier will ask for.
Is the Fire Hose Friction Loss Calculator free to use?+
Yes — completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.
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