How much electricity does a 1,500-watt heater use?

A 1,500-watt heater uses 1,500 watts an hour if it is left on the entire time; a heater left on around the clock for 24 hours uses 36,000 watts of electricity each day. To determine how many kilowatts the heater uses, divide the number of watts by 1,000.

Multiply the number of kilowatts by the price per kilowatt a utility company charges to determine how much it costs to run the heater each day. To save money on the electric bill, lower or turn off the main heater for the house, and use the 1,500-watt heater as a portable heat source that moves from room to room.