A 1000-watt space heater costs $0.18 per hour at the US average electricity rate of 18.44¢/kWh. That is $1.48 per day running 8 hours, about $44 per month, and about $538 a year at that pace. Use this guide to see exact costs for your state and usage pattern.
Formula: 1000W ÷ 1,000 × hours × your $/kWh rate = cost. The three columns use Idaho, the cheapest state at 12.35¢/kWh; the US average of 18.44¢/kWh; and Hawaii, the most expensive at 52.00¢/kWh. Rates are EIA Electric Power Monthly figures for May 2026 — a single month, not a 2026 annual average. Costs assume the heater runs at full rated wattage for every hour shown.