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Measured Liquid Flow Rate Calculator

Calculate a liquid flow rate from collected volume and elapsed time.

  • 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. Edit a calculated value to solve backwards, or 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

Divide collected liquid volume by the collection time in minutes. Collecting 10 US gallons in 30 seconds is a rate of 20 US gallons per minute.

Flow rate = collected volume ÷ elapsed time

Worked example

Enter these known values and leave the other values blank.

Volume
10 US gal
Time
30 sec
Flow rate
20 US gal / min

Assumptions and limitations

  • No. They represent different volumes. Choose the correct gallon unit and measure volume and time over the same interval. This average rate may differ from an instantaneous or peak flow.
  • Use the units shown beside each field. This model assumes the stated relationship and does not account for quantities left out of the formula.

Common questions

Are US and imperial gallons interchangeable?

No. They represent different volumes. Choose the correct gallon unit and measure volume and time over the same interval. This average rate may differ from an instantaneous or peak flow.

References

The calculation equations, inverse formulas, units, and input rules were imported from this source. Bookify provides the interface and equation solver.

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