How Much Does It Cost to Run a Sump Pump?
Short answer: about $0.14 a day and $4.15 a month, or $0.14 for each hour it runs at full power, at the 2025 US average electricity rate. That is for a 800 W sump pump running 2 hours a day with a 50% duty cycle. Change the state and hours below for your own number.
Updated Nov 8, 2026
Quick answer
Quick answer, US average (17.3 c/kWh)
About $4.15 a month
The same use costs $2.83 a month in North Dakota and $9.74 in Hawaii.
- Per hour
- $0.069
- with 50% cycling; $0.14 at full 800 W
- Per day
- $0.14
- 2 h, 0.80 kWh
- Per month
- $4.15
- 30 days
- Per year
- $50.52
- 365 days at the same use
Your state, your hours
Per hour
$0.069
Per day
$0.14
Per month
$4.15
Per year
$50.52
Sump Pump at 800 W, 2 h a day, 30 days a month, 50% duty cycle: 24.0 kWh a month. Using the 2025 US average of 17.3 cents/kWh.
Want to change the watts or duty cycle too? Open the full calculator.
What decides the cost of running a sump pump
A 1/3 HP sump pump draws about 500 to 900 W while running, and the default here uses 800 W. It switches on when the water in the pit lifts the float, empties the pit in well under a minute, and shuts off. The default of 2 hours a day at a 50 percent duty cycle works out to about an hour of actual pumping, 0.8 kWh a day and about $4.15 a month. That is a wet-season figure. In a dry month many sump pumps barely run at all, and in spring thaw or a week of heavy rain one can run far more.
Water table and drainage decide the cost, not the pump. Gutters that dump next to the foundation, ground sloping toward the house, and a high water table all send more water to the pit. Fixing downspouts and grading usually cuts run time more than any pump upgrade. A pump that cycles every minute or two in dry weather may have a failed check valve, letting the water it just pumped run back into the pit, or a discharge line draining back toward the house.
A bigger pump is not more expensive to run in any meaningful way. A 1/2 HP pump draws more watts but moves more water per minute, so it runs for less time to empty the same pit, and the total kWh ends up similar. What a larger pump changes is the start surge, which matters for backup power.
The real cost of a sump pump is the flood if it stops, and storms that bring the most water also bring outages. That is why backup matters more than efficiency here. For measuring, a plug-in meter between the pump and the outlet over a wet week gives your real number. Avoid smart plugs that can switch a sump pump off from an app.
How to cut it
- Extend downspouts at least 6 to 10 feet from the foundation to keep roof water out of the pit.
- Replace a leaking check valve so pumped water does not drain back in and get pumped twice.
- Pour a bucket of water into the pit a few times a year to test the float and pump.
- Add a battery backup pump, since the heaviest rain often comes with outages.
Sump Pump cost by state
Monthly cost for 800 W, 2 h a day, 50% duty cycle, 30 days, sorted cheapest to most expensive. Pick your state above to highlight it.
| Rank | State | Cents/kWh | Per month |
|---|---|---|---|
| 1 | North Dakota | 11.81 | $2.83 |
| 2 | Idaho | 11.82 | $2.84 |
| 3 | Nebraska | 12.34 | $2.96 |
| 4 | Louisiana | 12.57 | $3.02 |
| 5 | Arkansas | 12.84 | $3.08 |
| 6 | Montana | 12.98 | $3.12 |
| 7 | Utah | 13.07 | $3.14 |
| 8 | Washington | 13.11 | $3.15 |
| 9 | Oklahoma | 13.12 | $3.15 |
| 10 | Nevada | 13.15 | $3.16 |
| 11 | Tennessee | 13.18 | $3.16 |
| 12 | Kentucky | 13.24 | $3.18 |
| 13 | South Dakota | 13.38 | $3.21 |
| 14 | Wyoming | 13.38 | $3.21 |
| 15 | Missouri | 13.49 | $3.24 |
| 16 | Iowa | 13.72 | $3.29 |
| 17 | North Carolina | 14.02 | $3.36 |
| 18 | Mississippi | 14.03 | $3.37 |
| 19 | Kansas | 14.56 | $3.49 |
| 20 | Georgia | 14.73 | $3.54 |
| 21 | South Carolina | 14.96 | $3.59 |
| 22 | New Mexico | 15.08 | $3.62 |
| 23 | Florida | 15.24 | $3.66 |
| 24 | Virginia | 15.28 | $3.67 |
| 25 | Arizona | 15.32 | $3.68 |
| 26 | Oregon | 15.37 | $3.69 |
| 27 | West Virginia | 15.41 | $3.70 |
| 28 | Texas | 15.47 | $3.71 |
| 29 | Minnesota | 15.82 | $3.80 |
| 30 | Colorado | 15.85 | $3.80 |
| 31 | Alabama | 16.10 | $3.86 |
| 32 | Indiana | 16.23 | $3.90 |
| 33 | Ohio | 16.96 | $4.07 |
| 34 | Delaware | 17.13 | $4.11 |
| 35 | Illinois | 17.69 | $4.25 |
| 36 | Wisconsin | 18.16 | $4.36 |
| 37 | Pennsylvania | 19.30 | $4.63 |
| 38 | Maryland | 19.48 | $4.68 |
| 39 | Michigan | 20.01 | $4.80 |
| 40 | District of Columbia | 21.94 | $5.27 |
| 41 | New Jersey | 22.63 | $5.43 |
| 42 | Vermont | 22.92 | $5.50 |
| 43 | New Hampshire | 24.56 | $5.89 |
| 44 | Alaska | 26.09 | $6.26 |
| 45 | New York | 26.39 | $6.33 |
| 46 | Maine | 27.78 | $6.67 |
| 47 | Connecticut | 29.38 | $7.05 |
| 48 | Rhode Island | 29.46 | $7.07 |
| 49 | Massachusetts | 30.48 | $7.32 |
| 50 | California | 32.54 | $7.81 |
| 51 | Hawaii | 40.59 | $9.74 |
Rates: U.S. Energy Information Administration, Form EIA-861, annual average residential price, 2025 (eia.gov). Full list on the electricity rates by state page.
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Frequently asked questions
How much does it cost to run a sump pump per month?+
About $4.15 a month in the wet season. An 800 W pump on for 2 hours a day at a 50 percent duty cycle uses 0.8 x 2 x 0.5 = 0.8 kWh a day, or 24 kWh over 30 days, and 24 x $0.173 is about $4.15. In dry months it is often under $1.
How much does it cost to run a sump pump per year?+
Usually $15 to $50 a year. Running at this page's wet-season default all year would be 292 kWh, about $50.52, but most pumps run that hard only a few months a year.
How much does a sump pump cost per hour?+
About 14 cents for each hour of pumping. An 800 W pump uses 0.8 kWh an hour, and 0.8 x $0.173 is $0.14. Most cycles last well under a minute, so each one costs a tiny fraction of a cent.
How many watts does a sump pump use?+
About 500 to 900 W running for a 1/3 HP pump, and around 2,000 W for a moment at start. A 1/2 HP pump runs at about 1,050 W with a start surge near 2,500 W.
How much does it cost if a sump pump runs constantly?+
About $3.32 a day. 800 W for 24 hours is 19.2 kWh, and 19.2 x $0.173 is $3.32. Nonstop running points to a stuck float, a failed check valve, or groundwater coming in faster than the pump can move it.
Does a sump pump use a lot of electricity?+
No. Even in a wet month it uses about 0.8 kWh a day, less than a refrigerator. The cost to run is small next to the cost of a flooded basement if it stops.
Does a 1/2 HP sump pump cost more to run than a 1/3 HP?+
Only a little. On the same schedule a 1,050 W pump uses 1.05 kWh a day, about $5.45 a month, against about $4.15 for an 800 W pump. In practice the bigger pump empties the pit faster and runs less, so the difference is usually smaller.
What size generator do I need for a sump pump?+
One that can cover about 2,000 starting watts for a 1/3 HP pump or 2,500 for a 1/2 HP. A small 2,000 to 3,000 W inverter generator can run it with a little headroom, and the pump plugs into a regular 120 V outlet.
How long will a power station run a sump pump?+
About one hour of actual pumping from a 1,000 Wh station at 800 W, after about 15 percent inverter loss (850 / 800). Since the pump only runs in short cycles, that can cover a full day at this page's default, as long as the inverter can handle the 2,000 W start surge.
How can I lower the cost of running a sump pump?+
Send less water to the pit. Extend downspouts, regrade soil away from the foundation, and replace a failing check valve so the pump does not move the same water twice. The electricity saving is small, but the pump lasts longer.
Marcus Reed
Founder and Editor, CrunchYourDollars
Marcus Reed builds the sizing tools on CrunchYourDollars. He is a software engineer with a long-running PC hardware and power supply habit, which is where the watts, watt-hours and surge math on this site comes from. Product specs are pulled from manufacturer data sheets, electricity rates from the U.S. Energy Information Administration, and water chemistry rules from the Water Quality Association. He is not a licensed electrician or plumber: the tools show the math and the matching models so you can make the call, and anything involving your electrical panel should be checked by a licensed pro.
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