How Much Does a 1200W Space Heater Cost to Run?

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A 1200W space heater uses 1.2 kilowatt-hours (kWh) of electricity for every hour it runs continuously at full power. Your actual cost depends on your electricity rate and how often the heater cycles on and off.

Quick answer

The basic formula is:

Cost = heater power in kW × hours used × electricity price per kWh

For a 1200W heater:

1200W = 1.2kW

So if your electricity rate is $0.20 per kWh:

1.2 × $0.20 = $0.24 per hour

1200W heater running-cost examples

These examples assume the heater draws the full 1200W continuously. A thermostat-controlled heater may use less electricity over time because the heating element cycles off after the room reaches the selected temperature.

How to calculate your own cost

1. Find your electricity rate in dollars per kWh.
2. Convert the heater wattage to kilowatts by dividing by 1,000.
3. Multiply kilowatts by hours of use.
4. Multiply that result by your electricity rate.

Example: a 1200W heater used for 5 hours at $0.18/kWh:

1.2 × 5 × $0.18 = $1.08

Does a thermostat reduce the real cost?

Usually, yes—if the heater actually cycles the heating element off after reaching the set temperature. The nameplate wattage tells you the maximum draw while the heating element is running, not necessarily the average power over an entire evening.

Your real consumption depends on room insulation, outdoor temperature, drafts, thermostat setting, heater placement, room size and how often doors are opened.

What about Hexa Heat?

The current Hexa Heat merchant documentation lists a maximum power draw of about 1200W. That means the same calculation applies while the unit is operating at full output.

At $0.20/kWh, one hour at full 1200W output costs about $0.24. At $0.30/kWh, it costs about $0.36 per hour.

Read our Hexa Heat review for the product-specific safety, cost and performance considerations.

Can a 1200W heater save money?

A small heater can reduce total heating cost in some situations, but only if it replaces part of a larger heating load. For example, heating one occupied room while turning down the central system for the rest of the home may reduce total energy use.

Running a 1200W heater while leaving the rest of the home heated exactly as before does not create an automatic saving. It adds another electrical load.

Space heater vs heat pump efficiency

Electric resistance heaters convert electricity directly into heat at the point of use. Modern heat pumps work differently: they move heat rather than generating it entirely through electric resistance.

The U.S. Department of Energy says today’s heat pumps can reduce electricity use for heating by up to 75% compared with electric resistance heating such as furnaces and baseboard heaters. That means a 1200W portable resistance heater should not be assumed to be the cheapest electric heating option when a well-performing heat pump is available.

Source: U.S. Department of Energy — Heat Pump Systems.

How much does a 1200W heater use in 30 days?

The answer depends on daily runtime. At full power:

• 1 hour/day = 36 kWh per 30 days
• 4 hours/day = 144 kWh per 30 days
• 8 hours/day = 288 kWh per 30 days
• 12 hours/day = 432 kWh per 30 days

Multiply those kWh figures by your electricity rate to estimate monthly cost.

Is 1200W a heavy electrical load?

It is a meaningful continuous load. Portable electric heaters should be plugged directly into a suitable wall outlet rather than a power strip or extension cord. Stop using the heater if the plug, cord or outlet becomes unusually hot.

The U.S. Consumer Product Safety Commission also recommends keeping portable heaters at least three feet from bedding, furniture, curtains and other combustible materials, and turning them off while sleeping.

Source: CPSC portable-heater safety guidance.

Ways to reduce portable-heater running cost

• Heat only the occupied room rather than unused areas.
• Close doors where appropriate to keep heat in the target space.
• Reduce drafts around windows and doors.
• Use the thermostat instead of running continuously at maximum output.
• Do not overheat the room.
• Use suitable clothing and bedding so the thermostat can be set lower.
• Compare the cost with your existing central heating system rather than assuming the portable heater is cheaper.

How this applies to current heater offers

Hexa Heat is currently documented around a 1200W maximum. Top Heat’s current page is less consistent: its marketing copy says 500W, while the FAQ says 650W low / 1200W high. For a conservative Top Heat high-setting estimate, use the 1200W row until the merchant documentation is clarified. See our Hexa Heat vs Top Heat comparison.

Bottom line

A 1200W space heater uses 1.2kWh for every hour it runs continuously at full power. Multiply 1.2 by your electricity price to get the hourly cost.

At common example rates, that can range from about $0.12 per hour at $0.10/kWh to $0.48 per hour at $0.40/kWh. The real cost may be lower if the thermostat cycles the heater off, but it can also become substantial when the heater runs for many hours every day.

For the bigger decision, read our space heater vs central heating comparison and our portable heater safety and buying guide.