From Watts to Electricity Cost: Estimating Real Use
Power is a rate; cost also depends on time and tariff.
What it does and when to use it
A 1,000-watt appliance uses 1 kWh when it runs one full hour at that power. Thermostatic devices do not always run at maximum.
What information to enter
Enter watts, hours, days, and price per kWh. Use a duty-cycle percentage for equipment that cycles.
How to understand the result
The result estimates energy cost and may exclude tiered pricing, fixed charges, and losses.
Recommended step-by-step workflow
- Check the assumptionsA 1,000-watt appliance uses 1 kWh when it runs one full hour at that power. Thermostatic devices do not always run at maximum.
- Use matching unitsEnter watts, hours, days, and price per kWh. Use a duty-cycle percentage for equipment that cycles.
- Compare with another scenarioThe result estimates energy cost and may exclude tiered pricing, fixed charges, and losses.
Short example
A 1,500 W appliance used two hours daily consumes about 90 kWh in a 30-day month.
Common mistakes
- Confusing watts with kilowatt-hours.
- Assuming an air conditioner or refrigerator runs at full power continuously.
Frequently Asked Questions
What is a kWh?
A unit of energy: one kilowatt used for one hour.
How can actual use be measured?
A plug-in meter or utility data is more reliable than nameplate power alone.
Are my personal inputs saved?
No. The calculators and guides are designed for quick browser use without storing your personal input values.