About Electricity Cost Calculator
What It Does
This calculator estimates how much electricity each of your household appliances costs to run. Add devices from a library of 40+ common presets or enter custom wattage values, then see a breakdown of daily, monthly, and yearly costs based on your electricity rate.
Regional Rates
The calculator includes approximate national average electricity rates for 30+ countries to help you get started quickly. These are rough averages only — actual rates vary significantly by provider, plan, usage tier, time of day, and local taxes. For the most accurate results, enter the per-kWh rate from your own electricity bill.
How the Math Works
The formula for each appliance is straightforward:
Daily kWh = (Watts × Hours per day) ÷ 1,000
Monthly cost = Daily kWh × 30 × Rate per kWh
This gives you a simple average. Actual consumption may vary based on thermostat cycles (for AC units and refrigerators), usage patterns, and appliance efficiency ratings.
Appliance Presets
The preset wattages represent typical values for common household devices. Your specific appliance may use more or less power — check the label or manual for its actual wattage. For devices that cycle on and off (like refrigerators and air conditioners), the preset uses an estimated average draw rather than peak wattage.
Limitations
- Flat rate only — does not model tiered pricing, time-of-use rates, or demand charges
- Average wattages — presets are approximations; your device may differ
- 30-day month — monthly estimates use a fixed 30-day month
- No standby power — does not account for phantom loads when devices are off but plugged in
Privacy
Everything runs in your browser. No data is sent to any server.