Space Heater Cost Per Hour and Per Month

Answer first: 1,500 W × 1 h ÷ 1,000 = 1.5 kWh. At 18.31¢/kWh (dated US example) = ~27¢/hour. At 8 hours/day for 30 days = 360 kWh = $65.92/month — if it draws full power the whole time.

A heater on a thermostat does not. Use the duty cycle in the calculator: at 50% duty, that 8-hour day halves to $1.10/day. Table: 750 W ≈ 14¢/hr, 1,500 W ≈ 27¢/hr, 2,000 W (UK) ≈ 53p/hr at 26.32p — all before duty, all at the stated example rates. Check your bill rate and use it.