How To Estimate Your Monthly Electricity Consumption

- Aug 29, 2017-

Almost everyone gets their monthly electric bill and wonders how in the world they used that much electricity.

Instead of just turning to kilowatt-hour (kWh) calculators to get a guess, it’s good to know how to calculate your electric bill. A smart way to calculate is to figure out each appliance’s monthly electricity consumption. This way, you can see how much electricity each appliance is using per month, allowing you to realize where it is best to cut back and save.

Step 1: Figuring Watts Per Day

To calculate how much an appliance is costing you each month, first you need to figure out how many watts of electricity it uses per day. For example, most refrigerators use 300–780 watts, but let’s say you were one of the lucky ones who scored one that uses only 300 watts. To calculate how many watts your refrigerator uses per day, you would multiply the wattage (300) by the hours (24), to figure that you are using 7,200 watt-hours per day.


300 watts X 24 hours = 7,200 watt-hours per day

Step 2: Converting to Kilowatts

Next, you need to convert the 7,200 watt-hours per day to kilowatt hours per day (kWh per day) since monthly electricity bills measure in kilowatt hours (kWh). One kilowatt is equal to 1,000 watts, so to figure out the kWh per day that your refrigerator uses, you simply need to divide the watt-hours per day (7,200) by 1,000 for a total of 7.2 kWh per day.


7,200 watt-hours per day / 1,000 = 7.2 kWh per day

Step 3: Figuring Usage Over a Month

Now, you need to figure out how many kWh the refrigerator is using per month, not just per day. To do this calculation, you simply multiply the kWh per day (7.2) by 30 days to get 216 kWh per month.


7.2 kWh per day X 30 days = 216 kWh per month

Step 4: Figuring Overall Cost

Now you finally know your refrigerator is using 216 kWh per month and can figure out how much that is costing you per month. To calculate this cost, you will need to look at your latest monthly electric bill in order to see how much you are being charged per kWh. Let’s say that you pay 10 cents per kWh. To figure out how much the refrigerator is costing you per month, you multiply your kWh per month (216) by your electricity rate ($0.10) to get a grand total of $21.60 per month.


216 kWh per month X $0.10 per kWh = $21.60 per month1

Each one of your appliances should have a wattage label on it, allowing you to input that wattage number into this simple, four-step calculation. If you cannot find this label, the EPA has provided a list of typical wattage levels for your everyday devices.

Typical Wattage Levels:2

Coffeemaker: 900-1200 watts

Microwave: 750-1100 watts

Toaster: 800-1400 watts

Dishwasher: 1200-2400 watts

Washer: 350-500 watts

Dryer: 1800-5000 watts

Iron: 100-1800 watts

Ceiling Fan: 65-175 watts

Space Heater (40 gal): 4500-5500 watts

Hair Dryer: 1200-1875 watts

Laptop: 50 watts

Computer Monitor: 150 watts

Computer Tower: 120 watts

Television 19"-36": 65-133 watts

Television 53"-61": 170 watts

Now that you know all the necessary steps to figuring your appliances’ electricity consumption per month, it’s time to start calculating and saving!

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