Appliance Energy Cost Calculator

How to Use

1. Enter the appliance wattage. Type the wattage printed on the appliance label, power adapter, manual, or smart plug reading.
2. Add daily usage and quantity. Enter how many hours per day the appliance runs, how many identical units you use, and how many days per month it is used.
3. Set your electricity rate. Enter your local electricity price per kWh from your utility bill or tariff plan.
4. Review the cost breakdown. Click Calculate Running Cost to see daily, monthly, and annual cost, kWh use, standby share, and savings scenarios.

Formula

Tips for Better Estimates

Frequently Asked Questions

How do I calculate appliance energy cost?

Multiply watts by hours used per day, divide by 1,000 to get kWh per day, then multiply by your electricity rate. Monthly and annual costs come from multiplying the daily cost by the number of use days.

What electricity rate should I use?

Use the delivered price per kWh from your electricity bill if possible. That blended rate usually includes generation, delivery, and other usage-based charges, so it better reflects the real bill impact than the energy-only tariff.

Why is my appliance label wattage different from real usage?

Many appliances cycle on and off or change power level during operation. A refrigerator, air conditioner, computer, washer, or microwave may not draw its nameplate wattage continuously. A plug-in power meter gives the best real-world average.

Should I include standby watts?

Include standby watts when the appliance keeps drawing power while it is not actively being used, such as TVs, game consoles, chargers, printers, and some kitchen appliances. Leave it at zero if the device is fully disconnected or has no measurable standby draw.

Is monthly cost based on 30 days?

The calculator uses the days per month value you enter. The default 30.42 is the average number of days in a month across a year, while 30 is convenient for a simple billing-month estimate.