About the Aquarium Pump Calculator
Filter and pump flow rate needed for a tank, allowing for head loss.
Also known as: filter flow rate calculator, aquarium turnover rate, pump size for fish tank, gph filter calculator.
How to use this calculator
- Enter tank volume, stocking level, head height, loss through media and pipework.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
pump rating = volume × turnover ÷ (1 − losses)
Worked example
Using the values pre-filled in the calculator above:
- Tank volume = 180 litres
- Stocking level: Normal (6×)
- Head height = 1 m
- Loss through media and pipework = 25 %
the calculator returns:
- Pump rating needed: 1,714 L/hour
- Actual flow required: 1,080 L/hour
- Turnover rate: 6 × per hour
- In US gallons per hour: 453