Apr 11, 2023
Understanding your home’s energy consumption is important because lowering your energy usage is the fastest way to reduce your monthly electric bill. Every device or appliance in your home uses a certain amount of electricity, measured in kilowatt-hours (kWh). Your power consumption level is the total amount of kWh used in your home. It directly affects your energy bills and the rate a provider charges you.
How can I find the wattage of a device?
Most devices have a label listing how many watts they use. You can find this wattage label either on the device (usually on the bottom or back) or in the owner’s manual.
If you can’t find the wattage label, here are a couple of other options to determine how much power the device uses.
How to calculate kWh usage
To calculate your energy consumption, you’ll need to multiply an appliance’s wattage by the number of hours you use it in a day. That will give you the number of watt-hours consumed each day.
Calculate watt-hours per day
Device Wattage (watts) x Hours Used Per Day = Watt-hours (Wh) per Day
Example: A 125-watt television used three hours per day
125 watts x 3 hours = 375 Wh/Day
How many watts are in a kilowatt?
Your electricity bill is measured in kilowatt-hours (kWh), not watt-hours. One kilowatt is equal to 1,000 watts. To calculate how many kWh a device uses, divide the watt-hours from the previous step by 1,000.
Convert watt-hours to kilowatts
Device Usage (Wh) / 1000 (Wh/kWh) = Device Usage in kWh
Example: A television using 375 Wh of electricity per day
375 / 1000 = 0.375 kWh
Now that we know how many kWh the appliance uses per day, we can estimate that usage over a month. Let’s multiply by 30 days to simulate an average month.
Find your monthly energy usage
Daily Usage (kWh) x 30 (Days) = Approximate Monthly Usage (kWh/Month)
Example: A television using 0.375 kWh of electricity per day
0.375 kWh x 30 Days = 11.25 kWh/Month
In this example, a 125-watt television you use for three hours per day adds up to 11.25 kWh of energy per month. That is your television’s energy consumption.
To simplify your calculation you can use this CityPower calculator
https://www.citypower.co.za/customers/Pages/calculator.aspx