How Much Does a Space Heater Cost to Run? Electricity Calculator 2026
A standard 1,500W space heater costs $0.24 per hour to run at the US average electricity rate of $0.16/kWh. That works out to $1.92 per day (8 hours), $57.60 per month, and roughly $288 for a 5-month heating season. The actual cost depends on your local electricity rate, the heater wattage, and how many hours per day you run it.
The Formula: Watts × Hours × Rate
The cost formula is simple: Cost = (Watts / 1000) × Hours × $/kWh. For a 1500W heater running 8 hours at $0.16/kWh: (1500/1000) × 8 × $0.16 = $1.92/day. Multiply by 30 for monthly cost: $57.60. This formula works for any appliance — just plug in the wattage from the nameplate label.
Space Heater Cost at Different Rates
Your electricity rate makes a huge difference. At $0.10/kWh (cheap states like Louisiana, Idaho): a 1500W heater costs $1.20/day or $36/month. At $0.16/kWh (national average): $1.92/day or $57.60/month. At $0.25/kWh (expensive states like California, Connecticut): $3.00/day or $90/month. At $0.35/kWh (Hawaii, parts of New England): $4.20/day or $126/month. Check your rate at our Electricity Cost Calculator.
Space Heater vs Central Heat
Space heaters are only cost-effective for supplemental heating of one room. Running a 1500W space heater costs about $57.60/month for one room. A gas furnace heating an entire house might cost $80-150/month but heats every room. If you are heating more than 2-3 rooms with space heaters, central heat is almost always cheaper. The break-even point is typically around 3 hours per day — below that, a space heater wins; above that, central heat is more economical.
Electrical Safety Requirements
Space heaters draw 12.5A at 1500W/120V. Never use an extension cord — the NEC and every heater manufacturer prohibit this due to fire risk. Plug directly into a wall outlet on a 20A circuit with 12 AWG wiring. A 15A circuit can handle one 1500W heater but nothing else on that circuit. Keep 3 feet of clearance from combustibles. Look for heaters with tip-over protection and overheat shutoff. GFCI protection is recommended for bathroom or damp-area use.
| Wattage | $0.10/kWh | $0.16/kWh | $0.25/kWh | $0.35/kWh |
|---|---|---|---|---|
| 750W | $18.00 | $28.80 | $45.00 | $63.00 |
| 1000W | $24.00 | $38.40 | $60.00 | $84.00 |
| 1500W | $36.00 | $57.60 | $90.00 | $126.00 |
| 2000W | $48.00 | $76.80 | $120.00 | $168.00 |
Types of Space Heaters and Efficiency
All electric space heaters are approximately 100% efficient at converting electricity to heat (first law of thermodynamics). The difference is in how they distribute heat. Ceramic heaters heat the air and are good for whole-room warming. Infrared/radiant heaters heat objects directly — better for spot heating and feel warmer faster. Oil-filled radiators provide steady, even heat with no fan noise. Fan-forced heaters distribute warmth quickly but are noisier. The best choice depends on your use case, not efficiency.
Disclaimer: For educational reference only. Consult a licensed professional.