Home Energy Audit Calculator
Calculate the electricity cost of any home appliance.
Enter wattage, daily usage, and your electricity rate to see daily, monthly, and annual costs.
A home energy audit helps you understand exactly which appliances are costing you the most on your electricity bill. Once you know the cost, you can make smarter decisions about usage habits, upgrades, or replacements.
Formula:
Annual kWh = (Watts × Hours per day × Days per year) / 1000
Annual cost = Annual kWh × Electricity rate ($/kWh)
What is a kWh? A kilowatt-hour (kWh) is the standard unit for measuring electricity consumption. 1 kWh = running a 1,000-watt appliance for 1 hour. Most electricity bills charge between $0.10 and $0.30 per kWh depending on country and region.
- US average: ~$0.17/kWh
- UK average: ~$0.25/kWh
- Australia average: ~$0.28/kWh
- Canada average: ~$0.11/kWh
Common appliance wattages:
| Appliance | Typical Wattage |
|---|---|
| LED light bulb | 8 – 15 W |
| Laptop computer | 30 – 70 W |
| Desktop PC | 100 – 300 W |
| 40-inch LED TV | 35 – 100 W |
| Refrigerator | 100 – 200 W |
| Dishwasher | 1,200 – 2,400 W |
| Washing machine | 500 – 1,800 W |
| Clothes dryer (electric) | 4,000 – 6,000 W |
| Electric oven | 2,000 – 5,000 W |
| Microwave oven | 600 – 1,500 W |
| Air conditioner (window unit) | 500 – 1,500 W |
| Central air conditioner | 2,000 – 5,000 W |
| Electric water heater | 3,000 – 4,500 W |
| Pool pump | 750 – 2,000 W |
| Electric vehicle charger (Level 2) | 6,000 – 12,000 W |
| Space heater | 750 – 1,500 W |
| Hair dryer | 1,000 – 1,875 W |
| Coffee maker | 750 – 1,500 W |
Tips to reduce electricity costs:
- Switch incandescent bulbs to LED — saves 80% of lighting energy
- Run dishwashers and washing machines only when full
- Use power strips to eliminate standby (“vampire”) power draw
- Set your water heater to 49°C (120°F) — reducing 10°C saves 5–10% on water heating costs
- A refrigerator more than 10 years old may use twice the energy of a modern model
Reading your electricity bill: Your bill should show total kWh consumed and the rate per kWh. Divide your total bill by total kWh to get your effective rate including fees and taxes.