The amount of electricity used to run an electric blanket will vary between different types of blankets. The wattage of the blanket will determine how much electricity the blanket will use and the amount of time you need to have the blanket turned on to warm the bed.
Electric Blanket Watts ref 1
Electric blankets have tags attached that tell how many watts the blanket uses. Manufacturers use the highest watts, which is what the blanket uses on the high setting. Most blankets are rated at 60 watts for a single control and 100 watts for a dual control when used on high. However, most people will not use the highest setting, so the watts used per side will be 30 to 50 watts when the blanket is set on medium.
Watts Used ref 1 calcualtion
If you keep the electric blanket on for eight hours, you would use 480 (single control) to 800 (dual control) watts if you run the blanket controls set on high. You would use 240 (single control) to 400 (dual control) watts for eight hours if the blanket controls are set on medium.
Kilowatt-Hour Used ref 1 calculation
The number of kilowatt-hours (kWh) used are calculated by dividing the total watts per day by 1,000 (1 kilowatt = 1,000 watts). If the single control blanket uses 240 to 480 watts per night, it would use 0.16 to 0.48 kWh. If the dual control blanket uses 400 to 800 watts per night, it would use 0.40 to 0.80 kWh.
Cost of Electricity ref 1 cost projection
If electricity cost 8.5 cents per kilowatt-hour, it would cost you 14 to 41 cents per night using a single control blanket using 240 to 480 watts in eight hours. It would cost 34 to 68 cents per night with a dual control blanket using 400 to 800 watts in eight hours. Costs per kWh will vary depending on how much your utility company charges for each kWh.