PoolCalc

Variable-Speed Pump Savings Calculator

Your pump is probably the second-biggest energy user in your house. See what a variable-speed swap saves at your actual rate.

Current pump

Variable-speed replacement

$869
saved every year
5,110 kWh/yr you stop buying
$993
current cost/yr
$124
after replacement
Single-speed5,840 kWh/yr
Variable-speed730 kWh/yr
Add salt conversion → full payback picture
See the math

kWh/yr = watts ÷ 1000 × hours/day × 365. Yours: 5,840 kWh/yr now vs 730 kWh/yr after — at $0.17/kWh that's $993 → $124. The physics behind the drop is the pump affinity law: power scales with the cube of speed, so running longer at low RPM moves the same water for far less energy.

Frequently asked questions

How much does a variable-speed pool pump save?

Typically 70–90% of pump electricity. A 1.5 HP single-speed drawing 1,600 W for 10 h/day at $0.17/kWh costs about $990/yr; the same turnover at low RPM on a variable-speed pump can run under $150/yr.

Why do variable-speed pumps use so much less power?

The pump affinity law: power scales with the cube of speed. Half the RPM moves half the water but uses about one-eighth the power — so running longer at low speed wins big.

Are variable-speed pumps required?

In the US, DOE efficiency rules effective 2021 mean most replacement pumps above ~1 HP are variable-speed anyway. Many utilities also offer rebates — check yours before buying.