How much does a heated bird bath cost to run?

The short answer

• Monthly ceiling = label watts x 0.72 x your price per kWh. The 0.72 is 24 hours x 30 days, divided by 1,000.
• At the US average residential price for August 2026 (18.16 cents per kWh, EIA), that is about 13 cents a month for every watt: $19.61 for a 150 W heater running flat out.
• The same 150 W heater ranges from about $15.80 a month in Washington to $34.68 in Maine at August 2026 state averages.
• The label figure is maximum power (DOE). A thermostat switches the element off when the water is warm enough, so your real bill is lower than the ceiling.
• To get your real number, run the heater for a week through a plug-in electricity usage monitor and multiply the kWh it shows by your rate.

Take the watts printed on the heater's label, multiply by 0.72, then by your electricity price in dollars per kWh. That gives the most one 30-day month can cost. At the August 2026 US average of 18.16 cents per kWh, it works out to about 13 cents a month for every watt. A 150 W heater that never switched off would cost $19.61 a month.

Your bill will be lower than that, because a thermostat keeps the heater off part of the time. How much lower depends on your weather, and you can measure it in a week.

What the terms mean#

A heated bird bath is a basin with an electric heating element built in. A de-icer is a separate element you set in a basin you already own. Both do the same job: they keep a patch of water open when it would otherwise freeze. Most use a thermostat, a switch that turns the element on in cold weather and off once the water is warm enough. The cost math is the same for both kinds.

A watt (W) measures how fast a device draws power. The Department of Energy (DOE) says the wattage stamped on an appliance or its nameplate "is the maximum power drawn." So the label tells you the heater's top speed, not how long it runs.

A kilowatt-hour (kWh) is the unit on your power bill. It is 1,000 watts used for one hour. A 150 W heater has to run for about 6 hours 40 minutes to use one kWh. DOE's method is simple: watts x hours, divided by 1,000, gives kWh. Multiply kWh by your price and you have the cost.

Worked through: a 150 W bath in Michigan#

Take a bath with a 150 W label, plugged in on December 1. Suppose the thermostat never switches it off, which is the worst case.

1. Daily energy. 150 W x 24 hours = 3,600 watt-hours. Divide by 1,000: 3.6 kWh a day.
2. Monthly energy. 3.6 kWh x 30 days = 108 kWh.
3. Price. The US Energy Information Administration (EIA) put Michigan's average residential price at 22.99 cents per kWh in August 2026. That is $0.2299.
4. Monthly ceiling. 108 kWh x $0.2299 = $24.83.
5. Season ceiling. If you leave it plugged in for three months, that is 324 kWh, or $74.49.

That $24.83 is the most December can cost. A cold, windy week pushes the real figure toward it. A week of thaw pulls it well below, because the element barely runs. The same bath at the national average price tops out at $19.61.

Monthly ceiling by state#

These are our figures, worked from EIA's August 2026 state averages at 24 hours x 30 days. The four wattages are example values to show the spread. They are not a survey of heaters on sale, so read your own label and use the column nearest it, or run the formula.

The spread is wider than most people expect. A 150 W heater in Maine can cost more than twice what it costs in Washington. In New York the August price rose from 26.64 cents to 28.65 cents in a year, and the national average rose from 17.57 to 18.16. Connecticut went the other way, from 30.17 to 24.51.

Why the figures you find online look low#

Two things pull published figures down. The first is old prices. Many cost figures were worked out years ago and never updated. Even DOE's own worked example on its appliance page uses 11 cents per kWh. At 11 cents, our 150 W heater costs $11.88 a month flat out. At today's average it costs $19.61. That is 65 percent more for the same heater doing the same work.

The second is the thermostat. Some figures assume the heater runs only part of the day, but do not say how much of the day. That gives a smaller number, but you cannot check it. The ceiling in the table is a number you can check, and your real bill can only come in under it.

How to find your real number#

The ceiling is useful for one decision: can I afford the worst month? For the real figure, measure it.

DOE suggests a plug-in electricity usage monitor. You plug it into the outlet, then plug the appliance into the monitor. Leave it in place, and it shows the kWh used over any stretch of time. DOE says monitors are "especially useful" for devices that do not run all the time, which is exactly what a thermostat-controlled heater is.

1. Plug the heater in through the monitor during a cold spell.
2. Read the kWh after seven days.
3. Divide by 7 and multiply by 30 for a monthly figure.
4. Multiply by your price per kWh.

Do it once in your coldest month and you have a better number than any table can give you. The monitor has to sit where the plug sits, so keep it dry and off the ground, the same as the plug.

Is it worth the money?#

For most yards, open water in a freeze is worth more than the same money spent on seed. Snow is no substitute, because melting it costs a bird body heat. A heated bath draws birds that never come to a seed feeder at all, such as American robins and Eastern bluebirds in winter.

To put the cost in feeder terms: our first-year budget prices black oil sunflower at $1.35 a pound. A 150 W heater at the US average ceiling, $19.61 a month, costs about the same as 14.5 lb of that seed. You can run your own seed numbers through the bird seed cost calculator. The data behind both is explained in how our numbers are built.

If the cost is the problem, the free option still works. Carry out warm water once or twice a day and accept that it freezes between trips. The trade-offs between that, a heater and a sunny dark basin are set out in the winter water table. Never add salt, glycerine or antifreeze to save power. Those harm birds, and a heater is the only safe way to keep water open around the clock.

Keep the winter basin shallow, about 1 in, so birds drink rather than soak. Keep scrubbing it, too. A heated bath is still shared water, and shared water spreads disease just as a feeder does. Placement works the same as for a feeder: cover 10 to 12 ft away, as in where to put a bird feeder, and open ground around the basin so a drinking bird can see cats coming.

Plugging it in safely#

The Consumer Product Safety Commission (CPSC) gives three rules that apply here. Use only extension cords "labeled for outdoor use" for outdoor appliances. Use ground-fault circuit-interrupters (GFCIs) "inside and OUTSIDE the house." A GFCI is an outlet or breaker that cuts power fast when current leaks to ground, as it can through water. And replace worn, old or damaged cords.

Use a heater or de-icer rated for bird baths. Keep the plug connection out of the water and off wet ground. Run the cord where nobody will trip on it and where a shovel will not cut it.

What this answer does not cover#

These are state averages for August 2026, the latest month EIA had published when we checked. Your own rate depends on your utility, your plan and the season, and winter rates may differ from summer ones. The price per kWh on your bill beats any number on this page.

The table gives a ceiling, not a forecast. We found no independent measurement of how many hours a bird bath heater actually runs in a given climate, so we do not estimate it. The monitor method above is the way to get it.

The wattages are examples, not a market survey. Heaters on sale cover a range, and we did not gather their specs. Read your own label.

The table covers US states only, in US dollars. Canadian readers can use the same formula with their own rate in cents per kWh. And this page does not tell you whether a given heater, cord or outlet is safe. It only tells you what it costs to run. If your outdoor outlet has no GFCI protection, have that fixed before the heater goes in. For the rest of the cold-season station, see winter bird feeding and the month-by-month bird feeding calendar.

Frequently asked questions#

How much electricity does a heated bird bath use?

At most, its label watts times the hours it is plugged in, divided by 1,000. That gives kilowatt-hours (kWh), the unit on your bill. A 150 W heater plugged in for a 30-day month can use up to 108 kWh. It only uses that much if the element never switches off. A thermostat turns it off once the water is warm enough, so the real figure is lower. A plug-in usage monitor will tell you the true kWh for your heater in your weather.

How much does a heated bird bath cost per month?

Multiply the label watts by 0.72, then by your price per kWh in dollars. At the August 2026 US average of 18.16 cents, a 50 W heater tops out at $6.54 a month, 75 W at $9.81, 150 W at $19.61 and 250 W at $32.69. Those are ceilings for a heater that never switches off. Use the price on your own bill if you can, because state averages ran from 14.63 cents in Washington to 32.11 cents in Maine.

Why are the costs I see online so much lower?

Mostly because they were worked out at older electricity prices. Even the Department of Energy's own worked example on its appliance cost page uses 11 cents per kWh. At 11 cents, a 150 W heater running flat out costs $11.88 a month. At the August 2026 US average of 18.16 cents, the same heater costs $19.61. Some figures also assume the thermostat keeps the heater off part of the time without saying how much.

Does a heated bird bath run all the time?

Not if it has a thermostat. The element switches on in cold weather and off when the water is warm enough, so on mild days it may barely run. That is why the full-power monthly figure is a ceiling, not an estimate. How many hours it actually runs depends on your weather, wind and basin, and we found no independent measurement of it. A usage monitor left in line for a week gives you the real answer.

Is a heated bird bath safe to plug in outside?

Use a heater rated for bird baths, plug it into an outlet with ground-fault circuit-interrupter (GFCI) protection, and if you need an extension cord use one labeled for outdoor use. Those last two rules are the Consumer Product Safety Commission's. Replace any cord that is worn or damaged, and keep the plug connection out of the water and off wet ground.

Sources and further reading

1. Electric Power Monthly, Table 5.6.A: Average Price of Electricity to Ultimate Customers by End-Use Sector, by State, August 2026 and 2025 US Energy Information Administration Residential prices: US 18.16 cents per kWh (17.57 a year earlier) and every state price in the table on this page
2. Estimating Appliance and Home Electronic Energy Use (archived copy, January 2026) US Department of Energy, Energy Saver Wattage x hours / 1,000 = daily kWh; label wattage is the maximum power drawn; appliances that cycle; usage monitors measure kWh over time; worked example at 11 cents per kWh
3. Plug Into Safety! (NSN 18-07) US Consumer Product Safety Commission Use only extension cords labeled for outdoor use for outdoor appliances; use GFCIs inside and outside the house; replace worn or damaged cords