You'll need two pieces of information from your bill; the amount due for the current month
and the number of kWh (kilowatt hours) used. You can find the kWh usage in the meter
reading section of your bill.
The amount of electricity used by a space heater is measured in watts and expressed on
your utility bill as kilowatt hours (kWh). Technically speaking, kilowatt hours is the
product of power in kilowatts (1000 watts) and time in hours - not kilowatts per hour. But
for the purposes of this explanation, kilowatts per hour is sufficiently accurate.
Step 1. Determine cost per kWh (kilowatt hour)
The easiest way to do this is divide your total current monthly bill by kWh usage.
Monthly bill ÷ kWh usage = Cost per kWh
This isn't the most accurate way to determine the cost per kWh because all electric bills
include a customer service charge of $6 or more which in effect increases the cost per
kWh by 5-10% depending on the amount of your bill. So it's up to you, you can either use
the full billing amount or subtract the service charge before you divide it by the kWh
For the examples here I'm going to include the monthly service charge because you really
don't have the option to pay it. I typically spend around $69 a month for 438 kWh of
electricity. When I plug the numbers into the formula above it looks like this:
69 ÷ 438 = 0.158 So my cost per kilowatt hour is slightly less than 16 cents.
Not coincidentally, the cost per kWh equals the cost to run a 1,000 watt space heater for
Step 2. Determine the cost to run any wattage space heater per hour
Cost to run space heater per hour = heater watts x .001 x cost per kWh
For a 1,500 watt space heater at a rate of $0.158 per kWh, the formula looks like this:
1,500 x .001 x .158 = .237, or 24 cents per hour rounded up.
Step 3. Estimate monthly cost to run
Let's say I plan on running my 1,500 watt space heater every day of the month for 6
hours. This is how to figure out how much to budget for:
$0.24 (per hour) x 6 (hrs) x 30 (days) = $43.20.
How much will you pay?
Electric rates in New England are some of the highest in the country. The national
average according to the EIA is 12.5 cents per kWh. So whatever the rate is in your
area, you now have the know how to budget for monthly space heater use and avoid an
unpleasant surprise when you open your electric bill.
How Much Does It Cost To Run A 1,500 Watt Space Heater?
Most electric space heaters and
electric fireplaces are rated at
1,500 watts. This would be the
"high" setting on the heater.
However, most space heaters also
have a "low" setting or a
thermostat, so for the sake of
simplicity we'll assume the space
heater in this example is operating
continuously at the full power
setting of 1,500 watts.
Also, energy costs vary from region
to region. If you want to know how
much electricity your space heater
uses, you'll need a recent electric
bill to work along with the example.