Free · Water tank and vessels calculators 🏊

Volume and Pipe Flow Rate

Convert volume over time or calculate ideal volumetric flow from cross-section and mean velocity.

  • Formula & worked example
  • Private in your browser
  • No signup
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Calculator inputs

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How to use this calculator

  1. Enter the known values in the units shown. Results update as you type.
  2. Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
  3. Use the worked example to check the method. Reset restores the starting fields.

Private by default

Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.

Formula and method

In initial displayed units, Volume 120, Time 2 gives Flow rate 60.

Flow = volume/time = cross-sectional area×mean velocity; circular segment area = r² acos((r−h)/r)−(r−h)√(2rh−h²).

Worked example

Enter these known values and leave the other values blank.

Volume
120 L
Time
2 min
Flow rate
60 L / min

Assumptions and limitations

  • The model uses mean velocity across the wetted cross-section, without pressure losses or a velocity profile. Partially filled circular pipes use the indicated minor or major segment. Inputs describe positive volume, time, speed and physical fill geometry.
  • Use compatible measurement units. Clear an unknown before solving for it, and lock independent known values when comparing changes. Currency choices label amounts without exchange-rate conversion.

Common questions

Can I solve backward from the result?

Clear the unknown and enter independent known values. A rounded whole count cannot uniquely recover a continuous dimension; keep the original measured dimensions for procurement planning.

References

The circular-segment chord relation squares both the radius and the perpendicular center-to-chord distance. Bookify replaces the captured rounded US gallon with the exact 3.785411784-liter definition. The US fluid ounce uses one 128th of the exact US liquid gallon, replacing the rounded captured reciprocal factor. The international acre is exactly 43560 square international feet; Bookify replaces the rounded captured area factor.

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