Variable-Speed Pool Pump Savings Calculator

For most pools, 50–80% off the pump’s share of the electric bill — often $300–$800 a year. A single-speed pump runs flat-out at one speed; a variable-speed pump moves the same water at a much lower RPM, and because power rises with the cube of speed, running at half speed uses roughly an eighth of the power. You run longer to move the same gallons, but the energy still drops dramatically. Enter your current pump and run time above for your own number.

In almost every case, yes — and in many states they’re now required for new and replacement pumps. The energy savings typically pay back the higher purchase price within one to three years, and the pump then keeps saving for the rest of its life. They’re also quieter and easier on your plumbing and filter. The main exceptions are very small above-ground pools or pumps you barely run, where the dollar savings are smaller.

A typical single-speed pump draws 1,500–2,500 watts. Run 8 hours a day, that’s roughly 12–20 kWh daily — about $60–$100 a month at $0.17/kWh, and often a home’s single largest electricity user after heating and cooling. A variable-speed pump doing the same circulation at low speed can cut that to a fraction. The calculator above shows your pump’s daily, monthly, and yearly use.

First we work out how much water your current pump moves in a day: flow (GPM) × 60 × hours. Then we model a modern variable-speed pump moving that same volume at a lower speed. Flow scales with speed and power with the cube of speed, so the energy to move a fixed amount of water scales with speed squared — that’s the saving. We compare the two pumps’ yearly electricity cost at your local rate. Open “Show the math” under the result to see every step.

Longer than a single-speed pump, but at far lower power — many owners run 10–14 hours a day, or even continuously at very low RPM. The goal is the same: turn the water over at least once a day. Because low-speed running is so cheap, spreading the same turnover across more hours actually costs less, not more. The calculator lets you set the new pump’s run window so you can see the trade-off.

Usually within one to three swim seasons. A quality VS pump runs about $700–$1,200 installed, and saving $400 or more a year on electricity covers that quickly — sometimes faster if your utility offers a rebate (many do, often $200–$400). After payback, the savings are money in your pocket every month for the 8–10+ year life of the pump.

For a straight replacement, match or modestly exceed your current pump’s horsepower — a 1.5–2 HP variable-speed pump suits most residential pools. Bigger isn’t worse with a VS pump: a larger pump run at low speed is often more efficient and gives you headroom for a heater, salt cell, or water features. What matters is running it slowly day-to-day, which the speed control lets you do.

The yearly figures assume you run the pump every day. If you close the pool or only run it part of the year, scale the yearly cost and savings down to the months you actually run — the percentage saved stays the same. Flow and watts are typical figures at average plumbing resistance; use the adjust fields to enter your pump’s exact specs from its label or the reading on a variable-speed pump’s display.