Complete Guide to Electricity Cost Calculation
The Energy Cost Calculator computes monthly and annual electricity expenses for any appliance or system. Enter wattage, usage hours, and utility rate for instant kWh and dollar results.
Why Track Energy Costs?
- Budgeting: Predict monthly bills
- Savings: Identify high-usage devices
- Efficiency: Choose ENERGY STAR appliances
- Planning: Size solar or battery systems
Energy Cost Formula
kWh = (Watts × Hours × Days) / 1000
Cost = kWh × Rate
Average US Utility Rates (2025)
| State | Rate ($/kWh) |
|---|---|
| California | 0.28 |
| Hawaii | 0.42 |
| Texas | 0.14 |
| Louisiana | 0.11 |
| National Avg | 0.15 |
Common Appliance Costs (4 hrs/day, $0.15/kWh)
| Appliance | Watts | Monthly | Annual |
|---|---|---|---|
| LED Bulb (60W equiv) | 9 | $0.16 | $1.97 |
| Refrigerator | 150 | $2.70 | $32.40 |
| Window AC | 1000 | $18.00 | $216.00 |
| Space Heater | 1500 | $27.00 | $324.00 |
How to Reduce Energy Costs
- LED Lighting: 75% savings vs incandescent
- Smart Plugs: Schedule off-peak usage
- Insulation: Reduce HVAC load
- Time-of-Use Rates: Shift to off-peak
Conclusion
Understanding energy costs empowers smarter consumption. Pair with our Solar Output and Power Consumption tools to maximize savings.