Electric Bill Calculator
Calculate electricity cost from kWh, watts, and hours.
Supports custom rates for any currency.
Enter wattage, usage hours, and your electricity rate to calculate cost.
Electricity is billed per kilowatt-hour (kWh).
The formula:
- kWh = Watts × Hours / 1,000
- Cost = kWh × Rate per kWh
Example (metric and imperial contexts): A 100W bulb running 10 hours/day for 30 days:
- Energy = 100 × 10 × 30 / 1,000 = 30 kWh
- At $0.12/kWh (US avg): $3.60/month
- At EUR 0.25/kWh (EU avg): EUR 7.50/month
- At GBP 0.28/kWh (UK avg): GBP 8.40/month
Typical appliance consumption:
| Appliance | Watts | kWh/month (avg use) |
|---|---|---|
| LED bulb | 10 W | 3.6 kWh |
| Laptop | 50 W | 18 kWh |
| Refrigerator | 150 W | 108 kWh |
| Air conditioner | 1,500 W | 270 kWh |
| Space heater | 1,500 W | 360 kWh |
| Electric dryer | 3,000 W | 90 kWh |
Unit conversions:
- 1 kWh = 3,600,000 joules = 3,412 BTU