How Much Does It Cost to Run an Engine Block Heater in Washington? (2026)
Block heaters keep an engine warm in cold climates so it starts easily. Plugging in all night is common but unnecessary; two to four hours before a start achieves the same result at a fraction of the cost.
A typical engine block heater (750 W) costs $0.11 per hour, or about $13.42 per month at 4 hours a day in Washington. Average running cost
| Wattage | Per hour | Per day | Per month | Per year |
|---|---|---|---|---|
| Low 400 W | $0.060 | $0.24 | $7.16 | $28.63 |
| Typical 750 W | $0.11 | $0.45 | $13.42 | $53.68 |
| High 1,500 W | $0.22 | $0.89 | $26.84 | $107.35 |
Formula: watts ÷ 1000 × hours × price per kWh. Typical use is 4 h/day for about 120 days a year (the cold months) ≈ 360 kWh per year.
One hour of an engine block heater (0.75 kWh) is the same electricity as
- 4.2km in an electric car
- 7.5hours of TV
- 17hours of a laptop
- 83hours of an LED bulb
In Washington, with electricity at 14.9¢ per kWh (source: EIA Table 5.6.A, 2026-06), a typical engine block heater costs $0.11 per hour and about $53.68 per year at 4 hours a day. That is about 19% less than the national average for the US ($16.51 per month), because electricity in Washington costs 14.9¢ per kWh against 18.3¢ nationally. Each $1.00 of electricity buys roughly 8.9 hours of use.
How to lower the cost of running an engine block heater
- Use an outdoor timer set to switch on 3 hours before you leave.
- Skip the heater above about -15 C. Modern engines start fine.
- Combine with a battery blanket only in extreme cold.
Frequently asked questions
How much does it cost to plug in a car overnight?
A 750 watt heater for 10 hours uses 7.5 kWh. On a 3 hour timer it uses 2.25 kWh.
How long should a block heater be plugged in?
Two to four hours. Beyond that the engine gains no more heat.
Do block heaters cycle on and off?
Most basic ones run continuously. Thermostat models cycle and use less.
Cost by region
US states
- Alabama
- Alaska
- Arizona
- Arkansas
- California
- Colorado
- Connecticut
- Delaware
- District of Columbia
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- Rhode Island
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
Canadian provinces
Related appliances
- E-Bike Charger100 W typical
- Golf Cart Charger900 W typical
- Electric Scooter Charger80 W typical
- Electric Vehicle Charger (Home)7,200 W typical
Use the generic electricity cost calculator · Which uses more? Take the quiz