HEATING & COOLING

Space Heater Cost Calculator

Estimate hourly, daily, monthly, and annual electric heater costs.

Transparent formula User-controlled electricity rate Calculations stay in your browser
Standard plug-in heaters are usually 1500W on High, and 750W or 1000W on Low.
Leave at 100% if the heater runs constantly. Set lower if it clicks on and off.

Your estimate will appear here

Enter your inputs and click calculate to see the cost and energy breakdown.

Methodology

The calculator multiplies the wattage of your heaters by the hours they run and the duty cycle percentage. Since all electric resistance heating is 100% efficient, this direct conversion perfectly estimates energy use.

Sources and Methodology

Our calculations and recommendations are based on standard electrical engineering formulas and authoritative guidance from the U.S. Department of Energy (DOE), U.S. Energy Information Administration (EIA), and the ENERGY STAR program. Estimates are deterministic and do not account for external variables such as degrading appliance efficiency or fluctuating tier-based utility rates.

CALCULATOR QUESTIONS

Frequently Asked Questions

Find answers about wattage, runtime, electricity rates, estimated costs, and the limitations of this calculator.

Review the calculator formula →

WHAT YOU WILL FIND HERE

  • Input and unit guidance
  • Formula and worked-example explanations
  • Reasons actual costs may differ
What is thermostat duty cycle?
Most space heaters have a thermostat. Once the room reaches the target temperature, the heater turns off for a while, then back on. A 100% duty cycle means it runs constantly. A 50% duty cycle means it's on half the time. If your heater is always running because the room is cold or drafty, leave it at 100%.
Are some space heaters more efficient than others?
No. All electric resistance heaters are exactly 100% efficient. A 1,500W oil-filled radiator produces exactly the same amount of heat as a 1,500W ceramic fan heater. The only difference is how the heat is distributed (radiant vs. convection) and how long they retain heat.
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