How to calculate appliance wattage usage
To calculate the electricity consumption of your household appliances, you need to know three things:
- The Power Rating (in Watts) of each appliance.
- The Number of Hours it is used per day.
- Because electricity is billed in kilowatt-hours (kWh), we use the formula:
kWh = (Watts × Hours) / 1000
Calculating Cost
Once you have the total kWh, multiply it by your electricity provider's rate (usually in cents or dollars per kWh).
Cost = Total kWh × Rate
Example
If you have 5 LED bulbs (8 Watts each) running for 6 hours a day:
- Total Watts = 5 × 8W = 40W
- Daily Usage = 40W × 6 hours = 240 Wh
- In kWh = 240 / 1000 = 0.24 kWh
- If electricity costs $0.12/kWh, daily cost = 0.24 × 0.12 = ~$0.03