Garden & Outdoor calculator
What Pond Pump Size Do I Need?
Use pond volume, desired turnovers per hour, waterfall/filter lift to find pond pump rated-flow requirement.
Enter your measurements
What Pond Pump Size Do I Need uses pond volume, desired turnovers per hour, waterfall/filter lift and the other configured measurements to return pond pump rated-flow requirement with a formula written specifically for this tool.
- Pond volume — Required
- Desired turnovers per hour — Required
- Waterfall/filter lift — Required
- Estimated hose/filter head loss — Required
- Rated-to-real flow factor — Required
Pond pump rated-flow requirement
Enter the measurements above to calculate pond pump rated-flow requirement.
How the calculation works
V17 calculation: targetActualFlow=pondVolume×turnoversPerHour/3600; totalHead=staticHead+frictionLoss; requiredRatedFlow=targetActualFlow×flowLossFactor. The result is reported as Pond pump rated-flow requirement.
Worked example
Example: Pond volume = 5000 L; Desired turnovers per hour = 2; Waterfall/filter lift = 50 cm; Estimated hose/filter head loss = 50 cm; Rated-to-real flow factor = 1.2. Result: Required Rated Flow = 3.33 L/s; Total Head = 100 cm; Target Actual Flow = 2.78 L/s.
Before you decide
Recheck the limiting measurement before purchase or installation. This page calculates the stated geometry or quantity only; product-specific construction or installation details can still affect the final choice. For what pond pump size do i need, the limiting result on this page is pond pump flow requirement.
Direct measurement/geometry calculation. No external reference is required for the arithmetic itself; the result is derived only from the user-entered measurements and the formula stored in calculationLogicJson.
Frequently asked questions
What does the Pond Pump Size calculator tell me?
It returns pond pump flow requirement from the measurements entered on this page. The calculation is specific to pond pump size, so the result should be compared with the exact product or specification you are considering.
Which measurements should I take for pond pump size?
Measure pond volume, desired turnovers per hour, waterfall/filter lift, estimated hose/filter head loss, rated-to-real flow factor. Use clear, usable dimensions rather than nominal room or product labels.
Should I round the pond pump flow requirement?
Keep the calculated value for comparison, then choose a real product that meets or stays within the returned pond pump flow requirement while allowing for the clearances, tolerances or ratings shown by its manufacturer.