How much does it cost to run a sump pump?
About $2.12 a month on the typical usage below, at the U.S. average $0.1816/kWh. Set your own rate and usage and the figure updates instantly.
A sump pump only runs when the pit fills — cheap most of the year, more in a wet season.
Running a sump pump at 800W running 2% of 24 h costs about
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A sump pump looks like it should be a big line item on your electric bill — at 800 watts it draws more than a refrigerator. But a sump pump isn't a fridge that hums along all day; it's an on-demand machine that fires only when the pit fills past the float switch, pushes the water out in a minute or two, and shuts back off. That's why the calculator defaults to roughly half an hour of runtime a day: most of a sump pump's life is spent sitting silent, not pulling power.
That duty cycle also means your real bill tracks the weather more than it tracks the wattage. Through a dry stretch the pump may barely fire — a few cents a month. During heavy rain or spring snowmelt it can cycle every few minutes for hours on end, and that single wet week can cost more than the rest of the season combined. If your sump pump bill spiked, the pump didn't get less efficient — more water showed up in the pit.
What drives the cost of running a sump pump
- How often the pit fills, driven by rainfall, snowmelt, and your local water table — not by the pump's horsepower
- Pump wattage and horsepower: a 1/3 HP pump draws meaningfully less than a 1/2 HP or 3/4 HP model doing the same job
- Cycle length per run — a clogged discharge line, undersized pipe, or a failing check valve makes the motor work longer than it needs to each time it kicks on
How to cut it
- Don't oversize the pump for your pit — an oversized pump short-cycles (on-off-on-off in rapid succession), which burns more power and wears out the switch faster than a properly sized one
- Keep the pit, inlet screen, and check valve clean so the pump isn't fighting a clog and running longer per cycle than it should
- Grade soil and route downspouts away from the foundation — less groundwater reaching the pit means fewer cycles to pay for in the first place
- A battery or water-powered backup pump adds flood protection during outages, but it won't lower your everyday electric bill — budget for it separately from running cost
Data basis
- Electricity price
- U.S. Energy Information Administration, Electric Power Monthly, Table 5.6.B, June 2026 year to date, released 2026-08-26. Retrieved 2026-09-11. Average residential revenue per kWh. A benchmark average, not a utility tariff — it excludes the fixed charges, tiers, time-of-use windows, taxes and fuel adjustments on a real bill.
- Appliance energy
- A representative running power for a sump pump, compiled from published manufacturer specifications and public appliance-energy guidance, and presented as a typical figure with the usual range shown above. It is not a measurement of your unit, and we do not claim a single primary source for it — the nameplate on your appliance, or an hour with a plug-in energy meter, beats any typical figure we can publish.
- Usage model
- Cycling load — 800W running 2% of 24 h
- International prices
- rounded typical household tariffs for each market, in that market's own currency unless the row says US$ equivalent. These are planning benchmarks with no single primary source; enter the per-kWh price from your own bill for an accurate figure.
- Last reviewed
- 20 August 2026. Next scheduled review 20 February 2027.
- Corrections
- Think a figure is wrong? Tell us at corrections@watt-dollar.com and see our corrections policy.
Common questions
How much does it cost to run a sump pump per month?
On the assumption shown above — 800W running 2% of 24 h — a sump pump costs about $2.12 a month, or $25.45 a year, at $0.1816/kWh. That price is the U.S. average; set your own rate and usage above and the figure updates.
How is that worked out?
Running power x hours connected x the share of that time the motor actually runs. At 800W running 2% of 24 h that is 0.38 kWh a day, which at $0.1816/kWh costs $0.07 a day.
How can I cut the cost of running a sump pump?
Don't oversize the pump for your pit — an oversized pump short-cycles (on-off-on-off in rapid succession), which burns more power and wears out the switch faster than a properly sized one As a worked example: getting the run share down from 2% to 1.6% takes it from $25.45 to $20.36 a year, about $5.09 less.
Why is my electric bill so much higher in a wet month than a dry one, even though the pump didn't change?
Because runtime, not wattage, drives the cost. The pump's power draw is constant, but a wet week can mean hundreds of short cycles instead of a handful — that's the difference between a few cents and several dollars for the same appliance.
Does pump horsepower matter as much as how often it runs?
Less than you'd think. Moving from a 1/3 HP to a 3/4 HP pump raises the wattage, but doubling how often it cycles in a wet season raises the bill far more — runtime dominates the math for a pump you use in short bursts.