Darcy–Weisbach Calculator (Known f)
Direct head-loss computation when you already know the friction factor.
Darcy–Weisbach is dimensionally consistent and works for ANY fluid — unlike Hazen–Williams. Typical turbulent f in commercial pipe: 0.015–0.03.
Formula
Darcy–Weisbach Calculator (Known f) is a free darcy weisbach equation 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 Darcy–Weisbach Calculator (Known f)
Direct head-loss computation when you already know the friction factor. The calculation implements h_f = f·(L/D)·V²/2g (Moody (1944); Crane TP-410). Darcy–Weisbach is dimensionally consistent and works for ANY fluid — unlike Hazen–Williams. Typical turbulent f in commercial pipe: 0.015–0.03.
How to use Darcy–Weisbach Calculator (Known f)
- 1Enter Friction factor f.
- 2Enter Pipe length in m.
- 3Enter Pipe inner diameter in mm.
- 4Enter Velocity in m/s.
- 5Read Head loss, Pressure drop (water) instantly — no submit button needed.
- 6Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Darcy–Weisbach Calculator (Known f)?
- ✓Implements the standard formula — h_f = f·(L/D)·V²/2g
- ✓Reference cited on-page: Moody (1944); Crane TP-410
- ✓One-click SI ⇄ Imperial toggle — values convert in place, physics stays in SI
- ✓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 Darcy–Weisbach Calculator (Known f) use?+
It computes h_f = f·(L/D)·V²/2g, per Moody (1944); Crane TP-410. 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?+
Darcy–Weisbach is dimensionally consistent and works for ANY fluid — unlike Hazen–Williams. Typical turbulent f in commercial pipe: 0.015–0.03.
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 Darcy–Weisbach Calculator (Known f) 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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