Heaters cost about $0.15 to $2.50 per hour to run, depending on fuel, equipment efficiency, local energy rates, and how long the system operates. For a typical eight-hour day over 30 days, that can mean roughly $36 to $600 a month; the heater’s input rating and the home’s heating demand matter more than its advertised output alone.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| Electric space heater | $0.10/hour | $0.24/hour | $0.40/hour | 1,500-watt unit at $0.10-$0.27 per kWh |
| Gas furnace | $0.40/hour | $1.10/hour | $2.00/hour | Fuel cost varies by input and gas price |
| Heat pump | $0.10/hour | $0.25/hour | $0.60/hour | Typical compressor operation; cold weather can raise use |
| Monthly example | $24 | $58 | $480 | Eight hours daily for 30 days; equipment types differ |
Assumptions: illustrative U.S. energy prices and operating loads; actual bills depend on climate, thermostat settings, and runtime.
Typical heater running costs by equipment type
For a common 1,500-watt electric heater, expect about $0.16-$0.30 per hour at typical residential electricity rates. At eight hours a day, that is $38-$72 monthly. A gas furnace often costs around $0.60-$1.60 per burner-on hour, while a heat pump may use less electricity per unit of heat than resistance equipment.
These figures describe energy use, not the full utility bill. A furnace cycles on and off, so eight hours of heating demand may not equal eight hours of continuous burner operation. Space heaters also draw their rated wattage only while actively heating.
Electricity, gas, and heat pump rates compared
The calculation starts with the equipment’s energy input, not just the heat it delivers. Electricity is billed per kilowatt-hour (kWh); natural gas is commonly billed per therm. A heat pump’s efficiency lets it deliver more heat per kWh than an electric resistance heater in suitable conditions.
| Equipment | Typical energy rate | Example input | Estimated hourly cost | Eight-hour day |
|---|---|---|---|---|
| 1,500-watt resistance heater | $0.10-$0.27/kWh | 1.5 kW | $0.15-$0.41 | $1.20-$3.24 |
| Gas furnace | $0.80-$2.00/therm | 0.5-1.0 therm/hour while firing | $0.40-$2.00 | $3.20-$16.00 |
| Heat pump | $0.10-$0.27/kWh | 1-2.2 kW | $0.10-$0.59 | $0.80-$4.72 |
Estimates use example rates and operating inputs, not guaranteed equipment averages. Gas furnace input and heat-pump draw vary by model and load.
What raises the hourly price of a heater
Higher wattage, colder weather, and a higher utility rate increase running costs fastest. A 1,500-watt heater uses 1.5 kWh per hour; a 750-watt setting uses half as much. The basic electric calculation is .
For example, at $0.18 per kWh, a 1,500-watt heater running six hours uses 9 kWh and costs about $1.62. At $0.30 per kWh, the same use costs $2.70. Heat pumps may consume more power when outdoor temperatures fall below roughly 25-35°F, particularly if electric resistance backup engages.
For gas, a 60,000-BTU-per-hour input furnace uses about 0.6 therm per hour while firing because one therm contains 100,000 BTU. At $1.50 per therm, that is $0.90 per burner-on hour, before considering cycling and furnace efficiency.
How room size and insulation change monthly use
A small, closed room may need only a 750-watt heater, while a drafty 300-square-foot room can require a 1,500-watt unit to maintain comfort. Room dimensions are only a rough guide: ceiling height, window area, insulation, and outdoor temperature change the heat load.
Runtime is the key bridge between hourly price and the monthly bill. A 1.5-kW heater at $0.18 per kWh running four hours daily costs about $32 monthly; running ten hours daily costs about $81. Thermostats and cycling reduce consumption compared with continuous full-power use.
Regional electricity and gas prices shift the bill
Electric heater costs can be substantially higher in regions with costly electricity. A rate of $0.30 per kWh makes a 1,500-watt heater cost $0.45 per hour, three times the $0.15 cost at $0.10 per kWh. Utility rate plans, time-of-use pricing, and delivery charges can also affect the effective rate.
Natural gas prices and climate create a different regional pattern. Colder areas generally need longer furnace runtimes, while local gas rates vary. Using the rate on the latest utility bill gives a more useful estimate than a national average.
When a space heater beats central heat on cost
Heating one occupied room with a space heater can cost less than raising the thermostat for an entire home, especially when central heating serves unused rooms. It is not automatically cheaper: a resistance heater can be expensive if it runs all day, and a heat pump may deliver the same heat at lower electricity use.
Compare the cost of keeping one room comfortable, not the heater’s purchase price alone. A 1,500-watt unit used eight hours daily at $0.18 per kWh adds about $65 monthly. Avoid using portable heaters as a substitute for a malfunctioning central system without checking safety and operating costs.
Installation, maintenance, and repairs add separate charges
Portable electric heaters usually need no installation, but central furnaces and heat pumps have service expenses beyond fuel. A routine heating tune-up commonly costs $100-$250; repairs can range from about $150 for a basic part to $1,000 or more for major components. New furnace or heat-pump installation is a separate project cost, not part of the monthly run rate.
Labor estimate formula: Service labor often runs $75-$150 per hour, with diagnostic or minimum-call charges around $75-$200. Filter replacement and keeping vents clear can help maintain airflow, but cannot correct poor insulation or an incorrectly sized system.
Lower the heater bill by controlling hours and heat loss
The most dependable savings come from reducing unnecessary runtime without sacrificing safe operation. Lower the thermostat when rooms are unoccupied, close doors to unused areas, seal obvious drafts, and use a timer where appropriate. Comparing electricity plans may help, but check fees and time-of-use periods before switching.
Before buying a more efficient heater, estimate seasonal use: hourly cost multiplied by expected operating hours. For central systems, compare repair and replacement quotes using the same capacity and efficiency assumptions. Never cover a heater, place it near combustible materials, or use an unvented fuel-burning heater indoors unless the equipment is specifically rated for that use.