Cipolletti Weir Flow Calculator
Discharge over a trapezoidal (Cipolletti) weir — irrigation's favourite, no end-contraction math.
The 1:4 sloped sides compensate end contractions exactly, so the simple formula needs no correction terms — Cipolletti's 1886 gift to canal operators everywhere.
Formula
Disclaimer: This tool is for general informational and estimation purposes only and is not professional financial, tax, accounting or legal advice. All figures are estimates — verify with a qualified professional before making decisions. Read the full disclaimer.
Cipolletti Weir Flow Calculator is a free cipolletti weir for process, mechanical and water engineers — 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 Cipolletti Weir Flow Calculator
Discharge over a trapezoidal (Cipolletti) weir — irrigation's favourite, no end-contraction math. The calculation implements Q = 1.86·b·H^1.5 (SI) (Cipolletti (1886); USBR Water Measurement Manual). The 1:4 sloped sides compensate end contractions exactly, so the simple formula needs no correction terms — Cipolletti's 1886 gift to canal operators everywhere.
How to use Cipolletti Weir Flow Calculator
- 1Enter Crest length in m.
- 2Enter Head over crest in m.
- 3Read Discharge, Discharge instantly — no submit button needed.
- 4Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Cipolletti Weir Flow Calculator?
- ✓Implements the standard formula — Q = 1.86·b·H^1.5 (SI)
- ✓Reference cited on-page: Cipolletti (1886); USBR Water Measurement Manual
- ✓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 Cipolletti Weir Flow Calculator use?+
It computes Q = 1.86·b·H^1.5 (SI), per Cipolletti (1886); USBR Water Measurement Manual. 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?+
The 1:4 sloped sides compensate end contractions exactly, so the simple formula needs no correction terms — Cipolletti's 1886 gift to canal operators everywhere.
Does this work for any fluid?+
Yes — density and viscosity are inputs (with common fluids suggested in the field hints), so the same physics applies to water, oils, gases and process fluids. Compute always runs in SI internally, so unit mix-ups can't corrupt the result.
Is the Cipolletti Weir Flow 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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