📖 Overview
Use this tool to estimate electricity bills for appliances and plan your monthly energy budget.
⚙️ How It Works
Converts device wattage to kilowatt-hours (kWh) of consumption, then multiplies by usage days and electricity tariff rate to estimate monthly and annual cost.
The Formula
Monthly Cost = (Watts ÷ 1000) × Hours/Day × Days/Month × Rate ($/kWh)
| Watts | Device power rating in watts (found on label or manual) |
| ÷ 1000 | Converts watts to kilowatts (1 kW = 1000 W) |
| Hours/Day | Daily usage hours |
| Days/Month | Days used per month (default 30) |
| Rate ($/kWh) | Your electricity tariff per kilowatt-hour |
💡The average US electricity rate in 2024 is around $0.13/kWh, but it varies from $0.09 (Louisiana) to $0.34 (Hawaii). Check your utility bill for your exact rate.
Quick Reference
| Appliance | Typical wattage | Monthly cost* ($/kWh = 0.13) |
|---|---|---|
| Refrigerator | 150 W | ~$7.02 (24h) |
| Washing machine | 500 W | ~$3.90 (6h use) |
| Gaming PC | 300 W | ~$11.70 (10h) |
| LED bulb | 10 W | ~$0.39 (10h) |
| Air conditioner | 1500 W | ~$58.50 (10h) |
| Electric oven | 2400 W | ~$9.36 (1h) |
Practical Tips
💡 Always check the device label for actual wattage — manufacturer specs can vary.
💡 Use smart plugs with energy monitoring for accurate real-world consumption data.
💡 Air conditioners and electric heaters dominate household bills — focus here for big savings.
Frequently Asked Questions
❓ Where do I find my electricity rate?
It is listed on your monthly utility bill, usually as cents per kWh.
❓ What is a kilowatt-hour?
A 1000-watt device running for 1 hour uses exactly 1 kWh.
❓ Why is my bill higher than estimated?
Standby power, fluctuating usage, and taxes/fees add to the base energy cost.