How Much Does It Cost To Run an Electric Heater? (Calculator + Cost Charts)

"I've been running a 1,500W space heater in my home office all winter. My electricity bill jumped by $60 last month. How much is this thing actually costing me?"

If you're staring at a higher-than-usual electricity bill and wondering how much of it your space heater is responsible for, you're not alone. Electric heaters are one of the most common — and most misunderstood — appliances when it comes to energy costs.

Here's the quick answer: a standard 1,500-watt space heater costs about $0.25 per hour, $1.98 per day (8 hours), and $59.33 per month at the national average electricity rate of $0.1648/kWh (EIA, 2024). That's the "worst case" number — with a thermostat, your actual cost is typically 30–50% lower.

Before you can nail down your exact cost, you need three numbers:

1. Your heater's wattage (check the label — most space heaters are 750W or 1,500W)
2. How many hours per day you run it
3. Your electricity rate (check your utility bill; the national average is $0.1648/kWh)

Let's plug those numbers into our calculator.

Electric Heater Running Cost Calculator

The formula behind this calculator is simple:

Cost = (Wattage ÷ 1,000) × Hours × Electricity Rate ($/kWh)

Let's immediately put this to work with the most common scenario.

Example: You have a 1,500W ceramic space heater running 8 hours per day in Illinois at the state rate of $0.1587/kWh:

1. Heater wattage: 1,500W
2. Hours per day: 8
3. Electricity rate: $0.1587/kWh

Cost per hour: (1,500 ÷ 1,000) × $0.1587 = $0.24/hour Cost per day: $0.24 × 8 = $1.90/day Cost per month: $1.90 × 30 = $57.10/month Cost per winter season (5 months): $57.10 × 5 = $285.48

That's the math at full blast. If your heater has a thermostat (and most do), it cycles on and off to maintain temperature — which means actual runtime is typically 50–70% of "on" time in a well-insulated room (DOE Energy Saver). So that $57.10/month could realistically be $28–$40/month.

How Much Does It Cost To Run a Space Heater? (Per Hour, Per Day, Per Month)

Here's the deal: every electric heater converts electricity to heat at 100% efficiency. A 1,500W heater produces 1,500 watts of heat no matter the brand, type, or price tag. The only things that change your cost are wattage, runtime, and your electricity rate.

Let's break the costs down by wattage — the table below covers the four most common space heater power levels.

1,500 Watt Heater Cost Per Hour (The Most Common Scenario)

The 1,500-watt space heater is by far the most popular size in American homes. At the national average rate of $0.1648/kWh, here's what it costs:

Most 1,500W heaters draw about 12.5 amps on a standard 120V circuit. That's close to the safe maximum for a 15-amp circuit, which is why the DOE recommends plugging space heaters directly into a wall outlet — never an extension cord or power strip (CPSC, 2025).

Electric Heater Running Cost by Wattage (750W to 2,000W)

Below is the comprehensive cost table for the four most common electric heater wattages. All calculations assume the national average rate of $0.1648/kWh and 8 hours of daily use.

Source: Calculated using EIA 2024 national average residential electricity rate of $0.1648/kWh (EIA Table 5A).

As you can see, doubling the wattage doubles the cost. A 750W heater on the low setting costs just $29.66/month — roughly half the cost of running it at 1,500W.

If you're trying to keep costs down, you can check our heating cost calculator to compare your electric heater cost against other heating methods.

Electric Heater Cost Per Month (30-Day Running Costs)

The monthly cost question is the big one. Here's a quick-reference table for different usage patterns:

At $0.1648/kWh national average. Your local rate may differ — use the calculator above for your exact cost.

Pro tip: If your heater has a thermostat, the actual monthly cost is typically 30–50% lower than these numbers. A thermostat-controlled 1,500W heater set to 72°F in a well-insulated room may only run about 60% of the time, reducing that $59.33/month down to roughly $35–$40/month.

How Much Electricity Does a Space Heater Use?

Does a space heater use a lot of electricity? Yes — relative to most household appliances, space heaters are energy hogs. A 1,500W space heater draws more power than a refrigerator, a TV, and 10 LED light bulbs combined.

Let's put the numbers in perspective. A 1,500W space heater running 8 hours per day uses 12 kWh per day. The average U.S. household uses about 29 kWh per day total (863 kWh/month ÷ 30 days).

That means a single space heater can account for roughly 40% of your daily electricity usage when it's running.

Space Heater Wattage: How Many Watts Does a Space Heater Use?

Most portable electric space heaters use between 750 and 1,500 watts. The federal government caps portable space heaters at 1,500W for safety reasons — that's the maximum a standard 120V/15A household circuit can safely handle at continuous load.

Here's a breakdown of typical wattages by heater type:

Sources: Manufacturer specs (Cadet, King Electric, Stelpro); Angi baseboard heater guide.

How Many kWh Does an Electric Heater Use Per Day and Per Month?

To calculate kilowatt-hours (kWh), simply divide the wattage by 1,000 and multiply by hours of use:

kWh = (Wattage ÷ 1,000) × Hours

For context, the average U.S. household uses 863 kWh per month total. Running a 1,500W heater 8 hours a day adds 360 kWh — that's a 42% increase on top of your normal usage.

You can see how a space heater impacts your average electricity usage pretty dramatically.

Cost To Run Electric Heater by Type (Ceramic, Oil-Filled, Infrared, Baseboard)

All electric heaters are 100% efficient at converting electricity to heat. But different types have different effective costs because of how they deliver that heat and how they cycle.

All costs at $0.1648/kWh. "Effective cost" estimates account for thermostat cycling in a well-insulated room.

Ceramic Space Heater Running Cost

Ceramic heaters use PTC (Positive Temperature Coefficient) elements that self-regulate temperature. They heat up fast and are the most common type of portable space heater.

On low (750W), they cost just $0.12/hour. On high (1,500W), they cost $0.25/hour.

The advantage: ceramic heaters provide instant, directed warmth. The downside: they cool down immediately when turned off, so the thermostat needs to cycle frequently.

Oil-Filled Radiator Heater Cost Per Hour

Does an oil-filled heater use a lot of electricity? At face value, yes — an oil-filled radiator rated at 1,500W draws the same power as any other 1,500W heater ($0.25/hour).

But here's where oil-filled radiators have a real cost advantage: they continue radiating heat after the thermostat cycles off. The sealed thermal oil retains heat for 20–30 minutes between cycles. This means oil-filled radiators typically run only 40–60% of the time when thermostat-controlled, reducing the effective monthly cost from $59.33 to roughly $24–$36/month for 8 hours of daily use.

Infrared Heater Electricity Cost

Infrared heaters warm objects and people directly rather than heating the air. This means the room feels warmer at a lower thermostat setting — you get the same perceived warmth while the heater cycles less often.

At full power (1,500W), the cost is identical to any other electric heater: $0.25/hour. The energy savings come from the fact that you can often run an infrared heater at a lower setting and still feel comfortable.

Baseboard Heater Cost To Run Per Month

Electric baseboard heaters use 250 watts per linear foot — this is the standard density for 240V units (Angi, Gunnison County Electric). Here's the cost breakdown by length:

At $0.1648/kWh, 8 hrs/day. Based on standard density of 250W per linear foot.

Sizing rule of thumb: you need about 10 watts of electric baseboard heat per square foot of room space, assuming standard insulation and 8-foot ceilings. A 150 sq ft bedroom needs 1,500W (a 6-foot baseboard unit).

Electric Fireplace Running Cost

Electric fireplaces typically have two settings: 750W (low) and 1,500W (high). The flame effect itself uses only about 100 watts — so you can run the visual flame without the heater for just $0.016/hour (essentially free).

Running the full heater at 1,500W costs the same as any space heater: $0.25/hour or $59.33/month at national average rates.

Electric Heater Cost by State (Cheapest and Most Expensive)

Your electricity rate is the single biggest variable in your space heater costs. The difference between the cheapest and most expensive states is massive — more than 3x.

Here are the 10 cheapest and 10 most expensive states for running a 1,500W electric heater (8 hours/day, based on EIA 2024 annual data):

10 Cheapest States To Run an Electric Heater

10 Most Expensive States To Run an Electric Heater

The bottom line: running a 1,500W heater in Hawaii costs $154.30/month vs. just $41.44/month in North Dakota. That's a $112.86 difference per month for the exact same heater.

For a comparison of gas vs. electric heating costs by state, check our full breakdown.

Space Heater vs Central Heat: Which Is Cheaper?

This is the million-dollar question. And the answer is: it depends on how many rooms you're heating.

The U.S. Department of Energy states that space heaters can be less expensive when you only need to heat one room or supplement inadequate heating. However, using space heaters to heat your entire home costs about 43% more than a gas furnace, according to DOE data cited by multiple HVAC industry sources.

Here's the rule of thumb: a space heater only saves money if the heated area is less than ⅓ of your home's total floor space, and you turn down the thermostat for the rest of the house.

Space heater costs assume 1,500W units at 8 hrs/day, national average rate. Central heat assumes gas furnace with 80%+ AFUE.

Do Space Heaters Use More Electricity Than Central Heat?

Per BTU of heat delivered, electric resistance heaters (space heaters) are significantly more expensive than gas furnaces or heat pumps:

A heat pump delivers the same heat for about one-third the electricity cost of a space heater because it moves heat rather than generating it. If you're spending a lot on electric heating, check out our heat pump efficiency by temperature guide to see if a heat pump would be a better long-term investment.

The EPA has noted that lowering your thermostat from 70°F to 65°F and using a space heater to warm just 10% of your home's floor space saves a heat pump user about $67 per year (Stearns Electric / EPA). The savings increase with gas furnaces and in larger homes.

How To Reduce Electric Heater Running Costs

If you're committed to using an electric heater, here are the most effective ways to cut costs:

1. Use a thermostat-controlled heater. Heaters with built-in thermostats cycle on and off automatically, reducing actual runtime by 30–50% compared to constant-run models. The DOE specifically recommends thermostatically controlled heaters because they prevent energy waste from overheating a room.

2. Size the heater to the room. A 750W heater is plenty for a small office or bedroom under 100 sq ft. Running a 1,500W heater in a small room wastes energy. General rule: 10 watts per square foot.

3. Heat only occupied rooms. Turn the heater off when you leave. Every hour your heater runs empty is $0.12–$0.25 wasted. Pair this with lowering your central thermostat by 5–10°F for the rest of the house.

4. Improve room insulation. Better insulation means your heater runs less. Seal drafty windows, add weatherstripping to doors, and consider our insulation R-value chart to check if your insulation meets recommended levels.

5. Choose an oil-filled radiator for extended use. Oil-filled heaters retain heat between cycles, reducing effective electricity consumption by 40–60% for overnight or all-day heating.

6. Use a timer. Set the heater to turn off after you fall asleep or when you leave the room. Even cutting 2 hours off daily runtime saves $7.50–$15/month at national average rates.

7. Consider a heat pump instead. For long-term savings, a heat pump costs 2–3x less to operate per BTU than an electric heater. If you're spending more than $100/month on space heaters, it's worth looking at alternatives.

Worked Examples (With Real Electricity Rates)

Let's run through five real-world scenarios using actual state electricity rates.

Example 1: 1,500W Heater Running 8 Hours Per Day (National Average)

Scenario: You run a standard 1,500W ceramic space heater in your living room for 8 hours every evening.

1. Wattage: 1,500W
2. Hours per day: 8
3. Rate: $0.1648/kWh (national average)

Cost per hour: 1.5 kWh × $0.1648 = $0.25 Cost per day: $0.25 × 8 = $1.98 Cost per month: $1.98 × 30 = $59.33 Cost per winter (5 months): $59.33 × 5 = $296.64

With thermostat cycling (60% runtime): $59.33 × 0.6 = $35.60/month

Example 2: Baseboard-Heated Bedroom All Winter (New York)

Scenario: You have an 8-foot electric baseboard heater (2,000W) in your 200 sq ft bedroom in New York. It runs 10 hours per day (evening through morning) for 5 winter months.

1. Wattage: 2,000W (8 ft × 250W/ft)
2. Hours per day: 10
3. Rate: $0.2443/kWh (New York average)

Cost per day: 2.0 kWh × 10 hrs × $0.2443 = $4.89/day Cost per month: $4.89 × 30 = $146.58/month Cost per winter (5 months): $146.58 × 5 = $732.90

With thermostat cycling (65% runtime): $146.58 × 0.65 = $95.28/month

That's steep. If this is your situation, you might want to explore furnace sizing options or check AFUE ratings to see if upgrading your heating system would save money long-term.

Example 3: Home Office Space Heater All Winter (Texas)

Scenario: You work from home in Houston, Texas and run a 1,000W infrared heater under your desk for 8 hours per day, 5 days a week, for 4 winter months.

1. Wattage: 1,000W
2. Hours per day: 8 (only weekdays = ~22 days/month)
3. Rate: $0.1494/kWh (Texas average)

Cost per day: 1.0 kWh × 8 hrs × $0.1494 = $1.20/day Cost per month (22 workdays): $1.20 × 22 = $26.27/month Cost per winter (4 months): $26.27 × 4 = $105.07

That's quite reasonable. A 1,000W infrared desk heater used strategically during working hours is one of the most cost-effective ways to supplement heating. This approach is similar to how your air conditioner costs are managed — targeted use beats whole-house operation.

Example 4: Space Heater vs Turning Up the Furnace

Scenario: You spend evenings in your living room (250 sq ft) in a 2,000 sq ft home in Ohio. Option A: run a 1,500W space heater and lower the furnace thermostat by 8°F. Option B: keep the furnace at 70°F.

Option A (space heater + lower thermostat):

• Space heater cost: 1.5 kWh × 5 hrs × $0.1599 × 30 = $35.98/month
• Furnace savings: lowering thermostat 8°F saves roughly 8–10% on gas bill (DOE)
• Typical gas heating: $120/month → 10% savings = −$12.00/month
• Net cost: $35.98 − $12.00 = $23.98/month added

Option B (furnace only at 70°F):

• Gas furnace cost: $120/month (no change)

Verdict: In this scenario, using the space heater increases your total heating cost by about $24/month. The space heater only wins if the heated area is a much smaller fraction of the home, or if you lower the thermostat more aggressively (10–15°F). The heating BTU calculator can help you figure out how many BTUs your specific room needs.

Example 5: Same Heater — Hawaii vs North Dakota

Scenario: Running the same 1,500W heater for 8 hours per day in the most expensive state vs. the cheapest.

Hawaii ($0.4286/kWh):

• Cost per hour: 1.5 × $0.4286 = $0.64/hour
• Cost per month: $0.64 × 8 × 30 = $154.30/month

North Dakota ($0.1151/kWh):

• Cost per hour: 1.5 × $0.1151 = $0.17/hour
• Cost per month: $0.17 × 8 × 30 = $41.44/month

Difference: $112.86 per month — that's the power of electricity rates. The same heater, same usage, 3.7x cost difference. If you live in a high-rate state, the math shifts dramatically in favor of gas heating or heat pumps.

Frequently Asked Questions

Does a Space Heater Use a Lot of Electricity?

Yes. A standard 1,500W space heater uses 1.5 kWh per hour — that's more than almost any other household appliance. Running one for 8 hours a day adds 360 kWh per month to your electricity usage, which represents a 42% increase over the average household's 863 kWh monthly consumption (EIA, 2024).

How Much Does It Cost To Run a 1,500-Watt Heater for 8 Hours?

At the national average rate of $0.1648/kWh, running a 1,500-watt heater for 8 hours costs $1.98. Over a 30-day month, that's $59.33 (before thermostat cycling). With a thermostat, expect $35–$42/month actual cost.

Is It Cheaper To Run a Space Heater or Turn Up the Furnace?

A space heater is cheaper only if you're heating one room (less than ⅓ of your home) while turning down the central thermostat. For whole-house heating, a gas furnace costs about 43% less than space heaters, according to DOE estimates. A heat pump is even cheaper per BTU.

How Many kWh Does a Space Heater Use Per Day?

A 1,500W space heater running 8 hours uses 12 kWh per day. A 750W heater at the same runtime uses 6 kWh per day. Multiply your heater's wattage by hours of use, then divide by 1,000 to get kWh.

Are Oil-Filled Heaters Cheaper To Run Than Ceramic Heaters?

At the same wattage, oil-filled and ceramic heaters cost the same per hour to run. However, oil-filled radiators are more cost-effective over time because they continue radiating heat after cycling off.

This reduces actual runtime by 40–60%, making effective costs roughly $24–$36/month vs. $35–$42/month for a ceramic heater with thermostat cycling (both at 1,500W, 8 hrs/day).

How Much Does Baseboard Heating Cost Per Month?

It depends on the total length of your baseboard heaters. At 250W per linear foot and the national average rate, a 6-foot baseboard heater (1,500W) costs about $59.33/month running 8 hours per day. A typical baseboard-heated bedroom with 8 feet of baseboard (2,000W) costs $79.10/month at full runtime, or roughly $47–$55/month with thermostat cycling.

A Note on Safety

We'd be irresponsible not to mention this: the CPSC estimates that portable heaters are involved in approximately 1,600 residential fires per year, resulting in roughly 70 deaths and 160 injuries (2019–2021 average). The NFPA reports that space heaters account for 29% of all home heating fires and 77% of heating fire deaths.

The three most important safety rules:

1. Keep heaters at least 3 feet from anything flammable (curtains, bedding, furniture)
2. Plug directly into a wall outlet — never use extension cords or power strips
3. Turn off when leaving the room or going to sleep