Heated Bird Bath Cost to Run: Monthly and Winter Cost by Wattage

A 150-watt heated bird bath that never shut off would use 108 kWh in 30 days. At the U.S. average home rate of 18.16 cents per kWh (EIA, August 2026), that is $19.61 a month: the most it can cost, not the usual bill.

Quick pick: cost = watts ÷ 1,000 × hours a day × days × your rate. A thermostat cuts the hours, so the 24-hour number is your ceiling.

Heated bird bath cost to run

At 18.16 cents per kWh. 24 hours a day is the ceiling; 12 hours is our example of a thermostat cycling half the time, not a maker figure.

80 W de-icer, 24 h, 30 days: 57.6 kWh, $10.46

80 W de-icer, 12 h, 30 days: 28.8 kWh, $5.23

150 W bath, 24 h, 30 days: 108 kWh, $19.61

150 W bath, 12 h, 30 days: 54 kWh, $9.81

80 W, 24 h, 90-day winter: 172.8 kWh, $31.38

150 W, 24 h, 90-day winter: 324 kWh, $58.84

The formula, step by step

☐ Watts: on the label or listing. The API 650 bath lists 150 W; the K&H de-icer, 80 W.

☐ Kilowatts = watts ÷ 1,000. 150 ÷ 1,000 = 0.15.

☐ kWh = kilowatts × hours a day × days. 0.15 × 24 × 30 = 108.

☐ Cost = kWh × your rate in dollars. 108 × 0.1816 = 19.61.

☐ Season: use your number of freezing days. 90 days at 150 W around the clock is 324 kWh, $58.84.

Your rate, not the average

EIA's August 2026 table (released Oct. 23, 2026) shows how far rates spread. The same 150 W bath running nonstop:

U.S. average, 18.16¢: $19.61 a month

New England, 28.31¢: $30.57 a month

Massachusetts, 30.48¢: $32.92 a month

Your bill lists cents per kWh; swap it into the formula. August is the latest month EIA has published, and winter rates can differ.

Ways to spend less

☐ Pick a thermostat model. K&H says its de-icer turns on and off as needed; API says its No. 300 de-icer has a built-in thermostat. The API 650 bath also lists a built-in thermostat, but neither API listing says how often it runs, so use the 24-hour number as your ceiling.

☐ Lower watts: an 80 W de-icer in the bath you have costs about half as much as a 150 W bath at the same hours.

☐ No outlet? The National Wildlife Federation suggests a few heavy-duty plant saucers, swapping the frozen one for fresh water each morning.

☐ Unplug in thaws.

Safe setup

☐ Only use an extension cord outdoors if it's marked for outdoor use (CPSC).

☐ CPSC also says extension cords should only be used temporarily. For a season-long heater, plug into an outdoor outlet.

☐ No glycerin as antifreeze. NWF warns it can raise birds' blood sugar and mat feathers.

☐ Clean the bath regularly in winter too (NWF).

☐ Stones or sticks as perches help birds drink without soaking in very cold weather (NWF).

De-icer and heated bath (#ad)

As an Amazon Associate, Curb Calc earns from qualifying purchases.

K&H Bird Bath Heater, Super Ice Eliminator, 80W: thermostatically controlled and rated to keep water open at -20°F, per the maker. For a bath you already own. See it on Amazon

Allied Precision Industries (650) Heated Bird Bath, 20 in: 120 V, 150 W, with a hinged clamp-on rail mount you tip to dump old water, per the maker. See it on Amazon

Heated bird bath FAQ

How much does it cost to run a heated bird bath?

At most about $19.61 a month for 150 W at the U.S. average rate; $10.46 for 80 W. Thermostats cut that.

How many kWh does a heated bird bath use?

Watts ÷ 1,000 × hours. 150 W for 24 hours is 3.6 kWh a day.

Can I add glycerin to keep a bird bath from freezing?

No. NWF warns against it; use a heater or swap in fresh water.

Winter yard prep: winter mulch for perennials, frost cloth, blowing out sprinklers.

Watch Curb Calc on YouTube: youtube.com/@curbcalc

Sources: EIA Electric Power Monthly Table 5.6.A, Aug. 2026 data, released Oct. 23, 2026; National Wildlife Federation, 2014; CPSC Publication 5032; wattage and thermostat claims from the K&H, API 650 and API 300 Amazon listings.