Pond Pump Calculator

What size pond pump do I need?

gal
Turnover
Waterfall
in
ft

Choose a pump that delivers

1,800GPH

Flow needed at 6 ft of head. Pumps lose flow as head rises, so read the pump's flow chart at your head height, then check it against the manufacturer's recommendation.

6 ft head1,800 GPH12 in spillway1,500 gal pond
Turnover flow1,500 GPH
Waterfall flow1,800 GPH
Head to check6 ft

The right pump satisfies two needs: turning over the pond and feeding any waterfall. This gives the flow to shop for at your head height.

How it works

Turnover flow = pond gallons × turnovers per hour. Waterfall flow = spillway inches × gallons per hour per inch. The bigger of the two is the flow you need delivered at your head height.

Before you order

  • Read the pump's flow chart at your actual head, since a pump loses flow as it lifts.
  • Fittings and long pipe runs add friction, so size pipe generously.
  • Pick a slightly larger pump and throttle it back rather than running one flat out.

Common questions

How much flow does a waterfall need?

About 100 gallons per hour per inch of spillway for light flow, 150 for medium and 200 for a heavy sheet.

What is head height?

The vertical distance from the pond surface to where the water comes out, plus an allowance for pipe friction.