Heating & cooling
What Does a 1,500 W Space Heater Cost to Run?
Calculate a stated 1,500 W heater's electricity cost from active hours and your tariff. Keep thermostat cycling and direct-wall safety guidance clear.
At a continuous 1,500 W draw, a heater uses 1.5 kWh per hour. Multiply by your rate. Thermostat cycling changes actual energy. Follow direct-wall safety instructions.
On this page
A heater drawing a steady 1,500 W uses 1.5 kWh in one hour. That gives a simple running-cost scenario. Actual electricity can differ if the heater switches off at its temperature target or uses a different power setting.
Read the exact heater's rated input and safety instructions. This guide calculates a stated 1,500 W case; it does not claim every portable heater has that rating.
Calculate an hourly cost
Use 1,500 ÷ 1,000 × 1 hour × price per kWh. At an illustrative $0.20/kWh, continuous hourly electricity costs $0.30.
At $0.30/kWh, the same stated draw costs $0.45 per hour. Those prices are examples, not current local tariff information. Use your own variable rate.
The EIA electricity guide explains the conversion from watts and hours to kWh. Convert cents to currency units before multiplying.
Distinguish switched-on time from active time
A thermostat can cycle the heating element. Four hours with the control switched on may include less than four hours at the stated full draw.
For the continuous-power scenario, four hours at 1,500 W use 6 kWh. At $0.20/kWh, that costs $1.20. Thirty such days cost $36.
If the element operates for only two of those hours, its stated full-power energy is 3 kWh. Any other powered modes must be considered separately. Do not assign a guessed cycling percentage to your heater and present it as measured use.
Put safe use before a closer measurement
The CPSC advises plugging electric heaters directly into a wall outlet. It warns against extension cords and power strips and calls for at least three feet from combustible materials.
This guide does not recommend an intervening plug-in meter or smart plug for a portable heater. Use manufacturer data and a clearly stated runtime scenario. Ask a qualified professional if a suitable measurement is necessary.
Turn the heater off while sleeping and follow the manufacturer's supervision instructions. Do not run it unattended merely to use an off-peak electricity rate. Stop using equipment with damaged cords, overheating, or a fault.
Compare heating routines honestly
A heater's room-only electricity cost cannot show the complete effect of changing central heating. You would need the avoided central-system energy and the added portable-heater energy under comparable conditions.
Do not assume that every hour of portable heating saves an hour of central heating. The systems serve different areas and can operate differently. Purchase price and installation are also outside the hourly calculation.
Record a useful cost scenario
- Confirm the heater's actual input setting in its manual.
- State whether hours mean continuous heating or total switched-on time.
- Use the variable price for those operating hours.
- Label thermostat behavior as uncertain if it is unknown.
- Keep safety requirements ahead of timers or measurement changes.
Use the electricity calculator with stated watts and active hours. Its result is electricity for the entered scenario, not a full heating bill or proof that the setup is safe.
Sources
Source pages checked during research on 7 October 2026. Examples are Handy Daily calculations unless stated otherwise.