What does a 1,500-watt space heater really cost to run?
Short answer: a 1,500-watt heater running 8 hours uses 12 kWh. At the illustrative rate of $0.17/kWh that is $2.04 for the 8 hours. Use your own rate below.
How the number is calculated
12 kWh = 1,500 ÷ 1,000 × 8. A thermostat makes the heater switch off part of the time, so running flat out is a ceiling, not a measurement.
Ways to use less
Heat the room you are in and close the door.
Use the thermostat or timer so the heater cycles.
Seal visible drafts before buying a bigger heater.