How long should I run the pool pump?

Long enough for one turnover a day, typically 8–12 hours.

How do I find average depth?

(shallow + deep) ÷ 2 for a uniform slope.

Running longer at lower speed saves a lot of energy.

What size pump for a 12,000 gal pool?

About 25–40 gpm depending on run time.

Sand, cartridge or DE filter?

DE filters finest; cartridge saves water; sand is simplest.

When should I backwash?

When pressure rises 8–10 psi above clean.

Pool pump turnover calculator

Pool size, hours of filtration and turnovers per day: you get pool volume and the minimum pump flow.

Minimum pump flow

5.6 m³/h

Minimum pump flow5.6 m³/h
Pool volume58.596 yd³
Litres of water11834.908 gal
Flow in litres per minute24.655 gpm

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How it's calculated (visible formula)

volume = length × width × average depth; flow = volume × turnovers ÷ hours

Net geometric measurement, no waste.
Adjustable waste % for cuts and breakage.
Purchase rounded up to sellable units (boxes, bags, buckets, boards).

See methodology and formula versions

How to calculate it, step by step

Measure pool length and width.
Average depth = (shallow + deep) ÷ 2.
Work out the volume.
Pick daily run hours and turnovers.
Get minimum flow and match pump and filter.

Worked example: 26 × 13 ft pool, 4.6 ft average depth, 8 h run time

Volume: 44.8 m³ (11,840 gal)
11,840 ÷ 8 h ÷ 60 ≈ 25 gpm

→ A pump delivering at least 25 gpm against your system head.

Common mistakes

Sizing by rated flow without system head.
Too few hours in summer.
A filter smaller than the pump flow.

Pro tips

Check the pump curve at your real head.
The filter must handle the pump's flow.
Run during the hottest, busiest hours.
A variable-speed pump cuts energy use a lot.

From calculation to quote

Add labour, overhead and your margin, and generate the professional PDF.

Create quote Calculate margin & VAT

FAQs

How long should I run the pool pump?: Long enough for one turnover a day, typically 8–12 hours.
How do I find average depth?: (shallow + deep) ÷ 2 for a uniform slope.
Variable-speed pump?: Running longer at lower speed saves a lot of energy.
What size pump for a 12,000 gal pool?: About 25–40 gpm depending on run time.
Sand, cartridge or DE filter?: DE filters finest; cartridge saves water; sand is simplest.
When should I backwash?: When pressure rises 8–10 psi above clean.

Sources and standards

Maintained by Srikanta M · Formula v1.0.0 · Verified 2026-09-10 · Updated 2026-09-10 · Limits: quantity estimation, not structural design or site supervision.