Running a typical 1,500-watt space heater costs about 26 cents an hour at 17 cents per kWh. The exact cost depends on heater wattage, electricity rates, and how long it runs each day.
Say you want to warm a 12 by 14-foot bedroom on chilly nights, running a 1,500W heater for 8 hours. At 17 cents per kWh, that’s about $3.36 per night or around $100 a month if you heat every night. This article breaks down that cost, compares heater sizes, and shows smart ways to lower your bill.
You’ll also see how space heaters stack up against central heating and other fuel types, so you can decide what’s best for your budget and comfort this winter.
Are Space Heaters Expensive To Run? Cost Breakdown
Space heaters can be expensive to run when they heat for many hours, but a short daily run may add only a few dollars to your monthly bill. Oil-filled radiators and oil-filled heaters cost the same as other electric heaters at the same wattage because the oil stores and spreads heat; your bill follows the electricity they use.
This oil-filled radiator heater efficiently warms occupied spaces.
Calculate the running cost with this formula: watts ÷ 1,000 × hours × your electricity rate. At 17 cents per kWh, a 750-watt heater uses 0.75 kWh per hour, so 0.75 × $0.17 is 12.75 cents; a 1,500-watt heater uses 1.5 kWh, or 25.5 cents per hour.
Heater wattage
Energy per hour
Cost at 12¢/kWh
Cost at 17¢/kWh
Cost at 25¢/kWh
750 W
0.75 kWh
9¢
12.75¢
18.75¢
1,500 W
1.5 kWh
18¢
25.5¢
37.5¢
5,000 W
5 kWh
60¢
85¢
1.25 (example cost to run a 1,500 W heater for one hour at typical rates)
Hourly cost assumes the heater draws its full rated wattage for the entire hour.
The 750-watt setting is the lower-cost choice, while 1,500 watts is the practical upper limit for most plug-in heaters on a standard 120-volt household circuit. A 5,000-watt heater is a different class of equipment: it generally needs a properly sized dedicated circuit and shouldn’t be connected to an ordinary wall outlet or power strip.
Heater
Watts
Per hour
Per day (8 h)
Per month (30 days)
750 W heater
750 W
13¢
$1.02
$30.60
1,500 W heater
1,500 W
26¢
$2.04
$61.20
5,000 W heater
5,000 W
85¢
$6.80
$204.00
Calculated at 17¢ per kWh. Monthly comparison for eight hours of operation per day at 17 cents per kWh. The result assumes full-power operation, before thermostat cycling.
Check How Long The Heater Actually Runs
The thermostat usually lowers the real cost by switching the heating element off after the room reaches its set temperature. The fan or indicator may continue briefly, but the expensive part is the heating element. A heater that is powered for eight hours may heat at full output for only part of that time, depending on insulation, outdoor temperature, drafts and the temperature setting.
Worked Example
Say your 12 × 14-foot bedroom uses a 1,500-watt heater for eight hours a night over 30 days. Full-power use is 1.5 kW × 8 hours × 30 days = 360 kWh. At 17 cents per kWh, 360 × $0.17 = $61.20 for the month. If the thermostat keeps the element on for half those hours, the heating portion is about $30.60 instead, although the exact result depends on the room and weather.
Room12 × 14 ft
Heater1,500 W
Schedule8 hours per night for 30 days
Full-power result360 kWh, or $61.20 at $0.17/kWh
Oil-filled radiators can feel cheaper because they release heat steadily after the element clicks off, but stored heat isn’t free heat. The element still has to warm the oil, and the radiator eventually gives that energy to the room. A 1,500-watt oil radiator running for the same time uses the same 1.5 kWh per full hour as a 1,500-watt ceramic or fan heater.
Useful for thermostat control
DREO Space Heater
Product 1 suits a room where you want to limit runtime: its thermostat adjusts in 1°F increments from 41°F to 95°F, and its ECO mode gives you more control than leaving a 1,500-watt heater running continuously.
Use the supply rate shown in dollars per kWh, not the total bill divided by your monthly usage unless you want a rough all-in estimate. Delivery charges, fixed fees and taxes can make the final bill higher than the heater-only calculation.
Use A Wall Outlet
Plug an electric space heater directly into a wall outlet, never an extension cord or power strip. Keep at least 3 feet of clearance, and choose a model with tip-over and overheat protection plus a UL, ETL or CSA listing.
How Space Heaters Compare With Other Heating Options
Natural gas central heating is usually the least expensive to run per unit of heat, while a space heater can cost less overall when you heat one occupied room instead of the whole house. Infrared heaters aren’t inherently cheaper than other electric heaters, and an oil-filled portable heater costs about the same to run as any other heater with the same wattage.
For a fair comparison, electricity at 17 cents per kWh supplies about 3,412 BTU per kWh, so a resistance heater costs roughly $49.85 per million BTU delivered. The fuel figures below use stated example prices and typical heating efficiencies; your local bill, equipment and fuel quality can change the result.
Heating option
Assumption
Approximate delivered cost
Electric space heater
$0.17/kWh; 100% at point of use
Typical cost per million BTU based on current fuel prices and market averages
Natural gas furnace
Typical natural gas price per therm, assuming 95% furnace efficiency
Estimated cost per million BTU for natural gas at current market rates
Propane heater
Average kerosene price per gallon, assuming 80% heater efficiency
Approximate cost per million BTU for kerosene fuel based on typical prices
Kerosene heater
Average propane price per gallon, assuming 80% heater efficiency
Estimated cost per million BTU for propane fuel at typical prices
Diesel heater
Average diesel price per gallon, assuming 80% heater efficiency
Approximate cost per million BTU for diesel fuel based on current prices
Pellet stove
Typical pellet price per ton, assuming 75% pellet stove efficiency
Estimated cost per million BTU for wood pellets at average market prices
Example comparison only: fuel and electricity prices assumed above are not a quote for your area.
Those numbers use about 91,500 BTU per gallon of propane, 135,000 BTU per gallon of kerosene, and roughly 16.5 million BTU per ton of pellets. For example, propane works out as $3 divided by 0.0915 million BTU, then divided by 0.80 efficiency: about $41 per delivered million BTU. A gas furnace’s lower fuel cost usually wins for whole-house heating, although duct losses, furnace condition and service charges still affect the bill. Natural gas heater running costs go into that comparison in more detail.
The zone-heating exception
A whole-house furnace can be cheaper per BTU yet cost more on a Tuesday night because it heats every room. Say you normally heat 1,000 square feet but spend the evening in a 150-square-foot room: a 1,500-watt heater running for four hours uses 6 kWh, or 6 × $0.17 = $1.02. That can beat turning on central heat for the entire house, especially when the rest of the rooms can safely stay cooler.
Infrared heating follows the same arithmetic as a fan heater: 1,500 watts costs about 26 cents per hour at 17 cents per kWh when the heating element runs continuously. Infrared may feel warmer sooner because it warms people and nearby surfaces directly, which can let you lower the thermostat or run it for fewer hours. The electricity itself isn’t cheaper.
Oil-filled radiators also use electric resistance heat, so a 1,500-watt oil-filled model costs the same 26 cents per hour at full output as a 1,500-watt ceramic or infrared model. Its oil stores heat after the element switches off, smoothing the room temperature; it doesn’t create extra heat from each kilowatt-hour. See the practical differences between oil portable heaters before choosing one for overnight room heating.
Electric heat is more economical when you need heat in one room, use it for a short period, or don’t have a low-cost fuel system already installed. Natural gas, propane, kerosene, diesel and pellets can look cheaper per BTU, but fuel delivery, venting, maintenance and equipment costs matter; fuel-burning heaters also need the correct indoor rating, required ventilation and a working carbon monoxide alarm. For a whole home, compare the delivered BTU cost and the cost of heating unused rooms before calling any heater cheap.
Useful Tools and Heaters to Control Costs
Efficient space heaters and energy meters to manage your usage
Precise thermostat
DREO 1500W Space Heater
The thermostat adjusts from 41-95°F in 1°F increments, so you can avoid heating past the temperature you actually want. Its ECO mode and 34dB operation suit a bedroom, while the 1500W output still draws the full rated load when heating at maximum power.
Its 12-hour timer can shut the heater off after the room has had enough heat, helping prevent hours of accidental operation. The 41-95°F thermostat range and ECO mode give you more control over runtime, which is where the electric bill is won or lost.
The 70-degree oscillation spreads warm air across more of the room, while the thermostat lets you set a target from 41-95°F in ±1°F increments. Child-lock, tip-over protection, overheat protection and an ETL listing add useful safeguards for everyday indoor use.
Space heaters are expensive to run only when they heat an empty or poorly sealed room for hours; the fastest savings come from running them less, not from chasing a supposedly magical heater design.
Using a timer can help reduce running costs effectively.
1
Set The Thermostat And Timer
Use the built-in thermostat to hold a reasonable room temperature instead of leaving the heater on continuously. A programmable timer can shut it off when you leave, lower the schedule overnight, or start heat shortly before you need the room. A thermostat cycles the heating element off after the room reaches its setting, then turns it back on as the temperature falls.
2
Use ECO Or Lower Heat
Choose ECO mode or the lower wattage setting once the room is comfortable. A 750-watt setting uses half the electricity of a 1,500-watt setting while it is actively heating, though it may take longer to warm the room. Keep the heater on a hard, level surface, plug it directly into a wall outlet, and leave about 3 feet of clearance.
3
Seal The Room Before Raising Heat
Close the door to unused rooms and block obvious drafts around windows and doors with removable weatherstripping or a draft stopper. Close curtains after dark, but keep them clear of the heater. Sealing a gap costs less than paying to replace heat that escapes every few minutes.
4
Measure What The Heater Uses
A plug-in energy meter can show the heater’s actual wattage and how often the thermostat cycles. Check the reading at full power, then check it over several hours with the thermostat or ECO mode active. The long-run reading is more useful than the number printed on the heater because cycling changes the average.
5
Clean It And Remove Standby Use
Unplug the heater and let it cool before removing dust from the intake grille, outlet grille and filter if the manual includes one. Restricted airflow can reduce heat circulation and make the unit work poorly. After switching it off, unplug the heater once it has cooled if its display, remote receiver or controls continue drawing standby power; the meter will tell you if that load is present.
Useful for scheduled heating
DREO Space Heater
Product 2 suits a bedroom or office where you want timed heating because it includes a 12-hour timer, thermostat control from 41–95°F in 1°F increments, and an ECO mode; skip it if you need a heater for an unattended space, since portable heaters should not be left running unless the manufacturer specifically permits that use.
Calculated at 17¢ per kWh. Assumes 4 heating hours per day and an electricity rate of 17 cents per kWh; a thermostat may reduce the actual total by cycling the heater off.
Before The First Cold Night
Set the thermostat or timer so the heater isn’t warming an empty room.
Test ECO or the lower heat setting while you’re present.
Seal door and window drafts without covering the heater or its grille.
Clean dust from the intake and outlet with the heater unplugged and cool.
Use a plug-in energy meter if the electric bill still seems too high.
Use The Meter As A Reality Check
A heater that draws 1,500 watts for 4 hours uses 6 kWh; at 17 cents per kWh, that is $1.02 for that day. If the meter shows the unit cycles off for part of those hours, your actual cost will be lower.
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What Affects Your Space Heater’s Electricity Use Most
Space heaters aren’t automatically expensive to run; the bill comes from the heater’s wattage multiplied by its runtime and your local electricity rate. A 1,500-watt model uses the same electricity per hour whether its controls are simple or packed with electronics, while the thermostat can lower the total by switching the heating element off when the room reaches its setting.
Factor
What Changes
What You Can Control
Wattage
A 1,500 W heater draws more per heating hour than a 750 W model.
Choose enough output for the room, then use the lowest setting that maintains comfort.
Electricity rate
The same kWh costs different amounts by utility and location.
Check your latest bill; use that supply rate in the cost calculation.
Runtime
A heater running continuously costs more than one that cycles off.
Close doors, set a reasonable thermostat temperature and heat the occupied room.
Standby load
Electronic controls, displays or a remote receiver may use a small amount while idle.
Turn the heater off at its switch or unplug it when the manual allows and you won’t use it.
Condition
Dust-blocked air inlets and a dirty filter, where fitted, can cause poor operation or overheat shutoffs.
Clean the intake and filter as the manual directs; don’t operate a damaged cord or plug.
Wattage sets the hourly ceiling; runtime usually decides how often you reach it.
Wattage is fixed by the model, so room size matters before you buy. A heater that’s too small may run nearly nonstop and still leave cold corners; a larger heater doesn’t use its maximum wattage every minute if its thermostat cycles it off. Match the heater to the room and its insulation, then judge cost by the hours the element actually runs.
Worked Example
Say a 1,500 W heater runs at full output for 4 hours each evening, and your electricity rate is 17 cents per kWh. The calculation is 1.5 kW × 4 hours × $0.17, or about $1.02 per evening. If the thermostat keeps the element on for only half that time, the heating portion is about 51 cents instead. Your meter, rate plan and actual cycling decide the final number.
Heater1,500 W
Runtime at full output4 hours
Assumed rate$0.17/kWh
Heating costTypical monthly cost estimate for runnin
Running Cost Versus Breakdown Cost
A space heater’s electricity bill is separate from HVAC repair costs, including failed control boards or other electronics. Those repairs can make a central system expensive to own, but they don’t change the space heater’s wattage or the kWh price. Compare running cost with running cost, and repair or replacement cost with repair or replacement cost.
In short
The biggest levers are the heater’s wattage, your electricity rate and how long the heating element stays on. Standby electronics and sensible maintenance matter, but they rarely outweigh hours spent heating an empty room.
Questions People Ask
Are oil-filled radiators expensive to run compared to ceramic heaters?
An oil-filled radiator and a ceramic heater cost about the same to run when their wattage and runtime match. A 1,500-watt model draws about 26 cents per hour at 17 cents per kWh while powered. The oil-filled heater may cycle less often after warming up, but its stored heat doesn’t change the electricity used to reach the set temperature.
What is the least expensive type of space heater to operate?
The least expensive electric space heater is usually the one with the lowest wattage that still keeps your occupied area comfortable. Electric resistance heaters turn nearly all their electrical energy into heat, so ceramic, oil-filled and infrared models cost about the same at equal wattage. A lower setting, a thermostat, and heating one room usually save more than the heater label.
How does using a thermostat on a space heater save money?
A thermostat saves money by shutting the heating element off after the room reaches your chosen temperature. A 1,500-watt heater still costs about 26 cents per hour while actively heating at 17 cents per kWh, but cycling can reduce its average runtime. Keep the thermostat away from a cold draft or direct heat, or it may cycle poorly.
Can running multiple space heaters increase my electric bill significantly?
Yes, because the wattages add together. Two 1,500-watt heaters use 3,000 watts, or 3 kWh for every hour both run; at 17 cents per kWh, that’s about 51 cents an hour. Two heaters can also overload a standard 15-amp, 120-volt circuit, so use separate circuits and never connect either heater to an extension cord or power strip.
Is infrared heating more cost-effective than traditional space heaters?
Infrared heating isn’t automatically cheaper when the heaters use the same wattage. A 1,500-watt infrared heater and a 1,500-watt ceramic heater use roughly the same electricity per hour. Infrared can feel comfortable sooner when aimed at you or a nearby surface, which may let you heat less space or run it for less time.
How do propane and kerosene heaters compare in running costs to electric heaters?
Fuel cost depends on the local price, heater efficiency, and whether the model vents combustion outdoors; compare each heater’s fuel-use rating rather than BTUs alone. Propane and kerosene can cost less per unit of heat in some areas, but indoor use requires an indoor-rated heater, the ventilation specified by its manual, and a working carbon monoxide alarm. Use only 1-K kerosene in a kerosene heater, never gasoline, and don’t use outdoor or construction heaters indoors.
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