How many kWh does a space heater use per month?

A 1500W heater running 8 hours/day for 30 days uses 360 kWh/month — about $66 at the US average rate. A 1000W heater uses 240 kWh (about $44) and a 500W heater 120 kWh (about $22) on the same pattern.

Updated August 22, 2026

How Much Electricity Do Heaters Use?

Q: How much electricity does a space heater use?

A 1500-watt space heater uses 1.5 kWh of electricity per hour. Running 8 hours/day for 30 days uses 360 kWh/month. At the US average rate of 18.44¢/kWh (EIA Electric Power Monthly, May 2026), that costs about $66/month.

Q: Do space heaters use a lot of electricity?

Relative to other appliances, yes. A 1500W space heater draws as much as 150 ten-watt LED bulbs running at once. For zone heating — one room instead of the whole house — it can still work out cheaper than running central heating, as long as the rest of the house stays cool.

kWh Usage — Every Wattage from 200W to 5000W

A 1500-watt space heater — the most common size — uses 1.5 kWh per hour, 12 kWh per day (8 hrs), and 360 kWh per month (8 hrs/day). At the US average rate of 18.44¢/kWh, that costs about $66/month.

✓Formula: Wattage ÷ 1,000 = kWh per hour. Simple and exact.

Usage Table

kWh Usage by Wattage & Time Period

Monthly figures assume 8 hours/day for 30 days at full rated wattage. Cost column uses the US average rate of 18.44¢/kWh (EIA Electric Power Monthly, May 2026) — a single month, not a 2026 annual average.

Wattage	Typical Use	kWh/Hour	kWh/Day (4 hrs)	kWh/Day (8 hrs)	kWh/Month	Cost/Month
200W	Personal desk heater	0.2 kWh	0.8 kWh	1.6 kWh	48 kWh	$9
400W	Mini ceramic heater	0.4 kWh	1.6 kWh	3.2 kWh	96 kWh	$18
500W	Small heater (low)	0.5 kWh	2 kWh	4 kWh	120 kWh	$22
750W	Small room supplemental	0.75 kWh	3 kWh	6 kWh	180 kWh	$33
1000W	Bedroom / small office	1 kWh	4 kWh	8 kWh	240 kWh	$44
1200W	Medium room	1.2 kWh	4.8 kWh	9.6 kWh	288 kWh	$53
1500W ★ MOST COMMON	Standard space heater	1.5 kWh	6 kWh	12 kWh	360 kWh	$66
2000W	Large room	2 kWh	8 kWh	16 kWh	480 kWh	$89
3000W	Workshop / basement	3 kWh	12 kWh	24 kWh	720 kWh	$133
5000W	Industrial / garage	5 kWh	20 kWh	40 kWh	1200 kWh	$221

Context

How Heaters Compare to Other Appliances

Appliance	kWh Per Hour	Context
1500W Space Heater	1.5 kWh	Most common portable heater; draws its full rating while the element is on
LED Light Bulb (10W)	0.01 kWh	150× less than the heater, and it draws 10W steadily
Laptop (45W)	0.045 kWh	About 33× less; real draw swings with what it is doing
Refrigerator (150W)	0.15 kWh	150W while the compressor runs — it cycles, so a full day comes to far less than 3.6 kWh
Washing Machine (500W)	0.5 kWh	Rated draw while running; most of a cycle is well below it
Electric Dryer (5,000W)	5 kWh	The one household load that clearly beats a space heater
Central HVAC (3,500W avg)	3.5 kWh	Whole-home system; actual draw varies widely by equipment

Key insight: a 1500W space heater draws as much as 150 ten-watt LED bulbs running at once. For zone heating it still costs less than firing up central HVAC for the whole home to warm one room — but note that several of the appliances above cycle on and off, so their rated draw overstates what they actually use across a full hour.

FAQ

Heater Electricity Usage Questions

How much electricity does a space heater use?

A 1500-watt space heater uses 1.5 kWh per hour. Running 8 hours/day for 30 days uses 360 kWh/month. At the US average rate of 18.44¢/kWh, that costs about $66/month.

How many kWh does a 1500-watt heater use per day?

A 1500-watt heater uses 6 kWh per 4 hours, 12 kWh per 8 hours, 18 kWh per 12 hours and 36 kWh per 24 hours. Formula: wattage ÷ 1000 × hours = kWh.

Do space heaters use a lot of electricity?

Relative to other appliances, yes — a 1500W space heater draws as much as 150 ten-watt LED bulbs at once. For zone heating (one room instead of the whole house) it can still be more cost-effective than central heating, which draws several kilowatts for the whole home.

How many kWh does a 1000-watt heater use per month?

A 1000W heater uses 1 kWh per hour, 8 kWh per day (at 8 hrs), and 240 kWh per month. At 18.44¢/kWh, that costs about $44/month.

How can I reduce how much electricity my heater uses?

Run it for fewer hours — a timer or a thermostat that actually holds a setpoint is the single biggest lever, since cost is simply wattage × hours × rate. Drop from 1500W to 1000W where the room is small enough for it (roughly 10 watts per square foot). Seal drafts and improve insulation so the room holds its heat and the thermostat keeps the element off for longer. Ignore claims that one heater type sips less power than another at the same wattage: every electric resistance heater converts essentially all the electricity it draws into heat, so an "ECO" badge saves nothing by itself — it saves only if it actually runs the heater at lower wattage or for fewer hours.

How Much Electricity Do Heaters Use?

kWh Usage by Wattage & Time Period

How Heaters Compare to Other Appliances

Heater Electricity Usage Questions

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