The pump is usually the single biggest energy user on a swimming pool, because it runs for hours every day through the season. That makes running cost the question we are asked most often once a pool is up and going. The good news is that the largest savings do not need a whole new pump. They come from getting two things right: the size of the pump and how long it runs.
Work out what your pump actually costs
You can estimate the cost in four steps from the pump's data plate and your electricity bill:
- Find the pump's power rating in kilowatts (kW) on the data plate. If it is given in watts, divide by 1,000.
- Multiply by the hours you run it each day.
- Multiply by the days you run it in a season.
- Multiply by your electricity unit price in pounds per kWh, which is on your bill.
That gives a realistic seasonal figure, and it shows why a pump that draws even a few hundred watts more than it needs to, running several hours a day for months, adds up to real money.
A worked example: faster circulation costs more
Our guide to choosing a pool pump, first published back in 2017, has always been based on circulating all the water in the pool within an 8 hour period, and that remains the standard. In practice, though, many residential customers do not run the pump 24 hours a day, only for a few hours, so the real question is whether the pump clears the whole pool within the hours you actually run it. That is a straightforward sum of flow rate against run time: a higher flow rate circulates the pool in fewer hours.
The trade-off is cost. A pump that circulates faster, and so needs fewer hours, is a more powerful pump, and more power means more to run. You can work the running cost out simply: cost per hour equals the pump's input power in kilowatts multiplied by your electricity unit price in pence per kWh, because a 1 kW pump running for one hour uses 1 kWh.
At the time of writing (June 2026), Uswitch put the average UK electricity price at 24.67p per kWh. Take two models from the Plastica Argonaut AV Series at that price:
| Model | Input power | Max flow rate | Cost to run per hour | Energy cost per 1,000 litres moved |
|---|---|---|---|---|
| Argonaut AV50 | 0.45 kW | 216 litres/min | about 11p | about 0.86p |
| Argonaut AV250 | 1.80 kW | 533 litres/min | about 44p | about 1.39p |
So the AV250 moves more than twice the water per hour as the AV50 and would circulate a given pool in well under half the time, but it costs around four times as much to run each hour, and even measured per 1,000 litres moved it works out dearer. Faster circulation buys you shorter running hours, not lower cost. The lesson is the one that runs through this guide: choose the smallest pump that circulates your pool within the hours you intend to run it, rather than paying for speed you do not need.
Two notes on the figures: they use each pump's input power (what it draws from the mains, not its output), and the flow rates are the maximum at zero head, so the true flow at your system's head is a little lower and the per-litre cost a little higher. Electricity prices also change, so put your own unit rate from your bill into the sum above for an exact figure.
Right-sizing is the biggest lever
An oversized pump is the most common and most expensive mistake on a domestic pool. It costs more to run, it can overpower the filter by pushing water through too fast, and it strains the seals and shortens the pump's life. The aim is the smallest pump that comfortably turns your pool over in the target time, not the most powerful one that fits the pipework.
The target is one turnover through the filter every 8 hours for a domestic pool, or every 6 hours where bather loads are high. Work out the flow you need by dividing your pool volume in litres by the turnover hours, then by 60, to get litres per minute. Then choose a pump that delivers that flow at your system's head, not at the headline maximum on the box. Our Water Pump Performance Calculator and the calculator on our swimming pool pumps page both work this out and match it to our range, and the full method is in our guide to choosing a pool pump.
Run time is the second lever
You pay for every hour the pump runs, so running it only as long as needed to keep the water clear is a direct saving. Filtration need rises with temperature and bather load, so a pool often needs less running in cool, quiet spells than in a hot, busy week. Turning the pump down in the off-peak parts of the season, while still hitting your turnover target, cuts cost without affecting water quality.
Why efficient pumps matter, and the rule behind them
Pump energy use rises very steeply with speed and flow: push for a lot more flow and the power needed climbs out of proportion. That is the engineering reason oversizing is so costly, and the reason variable-speed pumps save so much on pools that use them, by running slower for longer. It is also why EU Ecodesign efficiency rules for water pumps have steadily pushed inefficient models out of the market, so a modern, well-made pump is already a more efficient starting point than an old one.
We do not stock budget pumps built to fail after a season or two. Every model is chosen for proven reliability and real-world efficiency. Two are worth knowing for running cost:
- The Plastica AG Series is our quietest pump, around 55 dB, well suited to above-ground and ornamental pools that run long and quiet.
- The Speroni SWIMM is a high-head, continuous-duty pump that holds its efficiency on demanding systems with long pipe runs, heaters or salt cells, where a weaker pump is pushed off its curve and wastes energy fighting the resistance.
For how the Plastica iFlo, AG and Argonaut sit alongside each other, see our guide to the Plastica range.
Small habits that protect efficiency
An efficient pump only stays efficient if the system is clean. A clogged strainer basket or dirty filter makes the pump work harder for less flow, which costs energy and wears the pump out early. Empty the basket regularly, keep the filter maintained, and make sure there are no air leaks on the suction side. These are the same checks that keep the pump reliable, so they pay twice.
Get the running cost right from the start
If you are sizing or replacing a pump, getting it right is what keeps running costs down for years. Use the pool calculator on the swimming pool pumps page, or call the team on 0115 987 0358 and we will help you match a pump to your pool.
Frequently asked questions
How much does it cost to run a swimming pool pump?
Take the pump's power in kilowatts from the data plate, multiply by the hours run per day, the days run per season, and your electricity unit price per kWh. Because pool pumps run for hours daily, an oversized or inefficient pump can cost noticeably more over a season than a right-sized one.
What is the cheapest way to reduce pool pump running costs?
Right-size the pump to your pool's turnover, and run it only as long as needed to keep the water clear. Those two levers usually save more than any single feature, and they do not require replacing the pump unless the current one is oversized or worn.
Are variable-speed pool pumps cheaper to run?
They can be, because pump power rises steeply with speed, so running slower for longer to hit the same turnover uses less energy. The same physics is why an oversized fixed-speed pump is expensive. A correctly sized, efficient pump on a sensible run schedule is the core of low running cost either way.
Does a dirty filter increase running costs?
Yes. A clogged strainer basket or dirty filter forces the pump to work harder for less flow, wasting energy and shortening its life. Regular basket and filter maintenance keeps both running cost and reliability in check.
Should I run my pool pump less in cooler weather?
Often yes. Filtration demand rises with temperature and bather load, so a pool usually needs less pump time in cool, quiet spells, as long as you still meet your turnover target. Reducing run time in off-peak periods cuts cost without harming water quality.
