How Much Does It Cost to Run a Space Heater?

Cost equals kilowatts × hours × electricity rate per kWh. Divide watts by 1,000 to get kilowatts, then use matching money units throughout the calculation.

For example, 1.5 kW × 4 hours × 16 cents equals 96 cents. If you enter the rate as 0.16 dollars instead, the result is 0.96 dollars.

Find the usage-based charges on your electricity bill, including delivery charges that rise with consumption. Leave out fixed monthly fees, since those won't change with heater runtime.

Time-of-use plans need separate calculations for each rate period. A heater used during expensive evening hours can cost more than the same heater used for an equal time off-peak.

How much does a space heater cost to run all day?

An 8-hour period at continuous full power costs 1.92 dollars at the example rate below. A thermostat may reduce consumption, but don't assume a particular reduction before you know how often heating pauses.

Runtime at 1,500 watts	Energy used	At 12 cents/kWh	At 16 cents/kWh	At 24 cents/kWh
1 hour	1.5 kWh	18 cents	24 cents	36 cents
4 hours	6 kWh	72 cents	96 cents	1.44 dollars
8 hours	12 kWh	1.44 dollars	1.92 dollars	2.88 dollars
30 hours total	45 kWh	5.40 dollars	7.20 dollars	10.80 dollars
8 hours daily for 30 days	360 kWh	43.20 dollars	57.60 dollars	86.40 dollars

These are continuous-power calculations, not forecasts for every home. The longer periods illustrate energy use, not a recommendation to leave a portable heater running unattended or while sleeping.

How much do different heater wattages cost to run?

Lower wattage costs less per active hour, but it may need more time to warm the room. Compare total kWh at a comfortable temperature rather than choosing solely by the smallest wattage.

Heater draw	Energy per hour	Hourly cost at 16 cents/kWh	Cost for 8 continuous hours
500 watts	0.5 kWh	8 cents	64 cents
750 watts	0.75 kWh	12 cents	96 cents
1,000 watts	1 kWh	16 cents	1.28 dollars
1,500 watts	1.5 kWh	24 cents	1.92 dollars

A lower setting suits a modest heating need once the room is warm. If it runs constantly without reaching a comfortable temperature, the room may need less heat loss or a different heating approach.

For an explanation of power settings and nameplate wattage, see how many watts a space heater uses.

Why can actual heater costs differ from the estimate?

Runtime, room heat loss, and the target temperature determine how closely your bill follows the full-power calculation. Drafts, open doors, and cold outdoor temperatures can keep the element on longer.

A thermostat setting is a temperature target, not a power setting. Turning it far above your desired room temperature usually just keeps heating on longer rather than making a fixed-power element heat faster.

For example, a heater drawing 1.5 kW for half of a 4-hour period uses about 3 kWh, plus any electricity used by controls or a fan between heating cycles. Don't apply that half-time assumption to a different room or colder day.

Our guide to whether space heaters use a lot of electricity explains why hours of use matter as much as wattage.

Who should choose the DREO Oil Filled Radiator?

The DREO suits someone seeking quiet room heat with built-in temperature control. Choose it for a room you occupy for several hours; skip it if your main need is a quick burst of warm airflow.

Its 600W, 900W, and 1,500W modes offer fixed power choices, while eco mode adjusts energy use to maintain the selected temperature. Those controls can limit unnecessary heating, but they don't promise a particular bill.

Oil-filled radiators warm gradually and keep releasing stored heat after the element switches off. That remaining warmth came from electricity already used, so it isn't free extra energy.

Use the built-in thermostat before considering an external controller. The remote, wheels, and handles suit room-to-room use, but let the heater cool before moving it.

Which electricity meter should you choose?

Choose the Plug-In Watt Meter for detailed readings or the Kill A Watt Meter for cost forecasts. Skip either for heater use unless both devices' manuals explicitly permit the connection.

A suitable load limit alone doesn't establish compatibility. If the heater requires a direct wall connection, keep it connected that way and use the calculation instead.

Plug-In Watt Meter: for readers tracking daily consumption

The MECHEER meter displays watts, accumulated kWh, cost, and electrical readings such as voltage and current. Its backlit display helps when the outlet sits in a dim spot, and memory retains accumulated readings after power loss.

Choose it if you want to compare consumption across normal occupied heating sessions. Skip it if the formula already answers your question or your heater's instructions rule out an inline device.

Its overload display is a warning, not permission to exceed any device or circuit limit. Follow the manual's setup instructions rather than relying on the default overload setting.

Kill A Watt Meter: for readers planning a monthly budget

The P3 Kill A Watt tracks kWh and projects costs by week, month, and year. Its backup retains accumulated information when power is interrupted.

Choose it if you want cost projections without doing every calculation yourself. Skip it if you only need an occasional wattage check.

Forecasts reflect the usage period behind them. A cold weekend with long heating hours won't represent a mild month spent mostly away from home.

How do you collect a useful energy reading?

Measure a normal occupied session and record the conditions, provided the connection is permitted. A few minutes during initial warm-up won't show how often the thermostat pauses later.

Follow both manuals for connection, limits, and setup.
Record the starting kWh or reset the session counter.
Note the heat mode, target temperature, and elapsed time.
Record the final kWh and multiply the difference by your electricity rate.

Repeat across several typical days if your schedule or weather varies. Change one setting at a time so you can tell what caused any difference.

Keep the heater unplugged and cool while cleaning it according to its manual. Clear dust from accessible grilles, keep openings uncovered, and stop use if the cord, plug, or outlet shows damage or overheating.

Can the DIGITEN thermostat lower heating costs?

The DIGITEN suits a compatible heater that needs temperature control at the occupied part of the room. Skip it if your heater already holds a comfortable temperature or doesn't allow external switching.

Its sensor sits in the remote controller, and the receiver switches power at the selected temperature. The maximum load is 15 amps and 1,800 watts, but compatibility also depends on both manuals and the heater's restart behavior.

Keep the remote and receiver in the same room. Place the sensor away from direct heater output, sunlight, and drafts, and supply the remote's 2 AAA batteries, which aren't included.

Don't chain a meter, thermostat, and other adapters together. An external thermostat doesn't replace supervision or make an unsuitable electrical connection acceptable.

Is a space heater cheaper than central heat?

It can be cheaper to heat one occupied room while reducing central heating elsewhere. Adding portable heat without changing the central setting usually adds consumption.

Central heat pumps can deliver more heat per unit of electricity than resistance space heaters. Gas and other fuel systems require a comparison that includes fuel rates and system efficiency.

Avoid lowering central heat enough to risk freezing pipes or leave other occupied rooms too cold. See whether a space heater is cheaper than central heat for the full comparison.

Which mistakes raise costs or create problems?

Excess runtime and poor setup are the main mistakes to avoid. Start with a safe heating spot, then reduce the heat the room loses.

Heat the occupied room rather than leaving doors open to unused spaces.
Use the lowest comfortable temperature instead of leaving the thermostat at maximum.
Keep at least 3 feet between the heater and curtains, bedding, furniture, or other combustible items.
Turn the heater off before leaving the room or sleeping.

Position the heater near a suitable wall outlet without stretching the cord across a walkway. Read our guide to space heaters and extension cords before trying to solve an outlet-location problem with extra cable.

The U.S. Department of Energy's portable heater guidance covers placement and electrical precautions.

For model choices, compare energy-efficient space heaters by controls and room needs rather than savings slogans.

How should you decide what to buy?

Calculate your current space heater running cost before buying equipment. Daily kWh × heating days × your electricity rate gives a monthly estimate; 5 kWh daily for 25 days at 16 cents per kWh equals 20 dollars.

Keep your current heater if its controls meet your needs and the estimated cost fits your budget. Choose a permitted meter for measurement, DIGITEN for compatible external temperature control, or DREO when you also need quiet room heat.

To compare heater types, use our space heaters for home guide. If you only need to work out how much it costs to run a space heater you already have, start with its wattage and selected settings.

Frequently asked questions

How much does it cost to run a 1,500-watt space heater for 8 hours?

A 1,500-watt heater running continuously for 8 hours uses 12 kWh, costing 1.92 dollars at 16 cents per kWh. Multiply 12 by your own electricity rate for your estimate; a lower power setting or thermostat breaks can reduce consumption during the same elapsed period.

Does a space heater use 1,500 watts all the time?

No, a heater with a thermostat may pause heating once the room reaches its target temperature, and lower power settings draw less electricity. The rated maximum helps you estimate continuous full-power use; actual daily consumption depends on the selected mode, room conditions, and active heating time.

How can I find my space heater's electricity cost?

Multiply kilowatts by active heating hours and your electricity rate per kWh, or multiply measured kWh directly by that rate. Use an inline meter only when both manuals allow the connection; if either requires a direct wall connection, estimate from wattage or use utility interval readings instead.

Is it cheaper to run a space heater or central heat?

A space heater can cost less when it heats one occupied room and lets you reduce central heating elsewhere. Savings depend on your central system, energy rates, and schedule; adding portable heat while keeping the same central setting usually adds energy use rather than replacing it.

How Much Does It Cost to Run a Space Heater?