Electricity Cost Calculator
Calculate daily, monthly, and annual electricity costs for any appliance based on wattage and usage hours.
Monthly Cost
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Daily Cost
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Annual Cost
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kWh / Month
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What is Electricity Cost Calculator?
The Electricity Cost Calculator estimates how much it costs to run an electrical appliance based on its wattage, daily usage hours, and your local electricity rate. It breaks down costs by day, month, and year.
How to use
- 1 Enter the appliance wattage (found on the label or in the manual).
- 2 Enter how many hours per day the appliance runs.
- 3 Enter the number of days per month (default 30).
- 4 Enter your electricity rate in dollars per kWh — check your utility bill (US average is about $0.13/kWh).
- 5 Click Calculate to see your daily, monthly, and annual costs.
Formula
Example calculation
A 1500 W space heater running 8 hours/day at $0.13/kWh: 1500 × 8 / 1000 = 12 kWh/day. Daily cost = $1.56. Monthly (30 days) = $46.80. Annual = $561.60.
Frequently asked questions
Where do I find my electricity rate?
Check your utility bill — look for the per-kWh charge. The US residential average is around $0.13–0.16/kWh, but rates vary widely by state and provider.
What is a kWh?
A kilowatt-hour is the energy used by a 1000 W appliance running for one hour. It is the standard billing unit for electricity.
How do I find an appliance's wattage?
Check the label on the back or bottom of the appliance, the owner's manual, or search the model number online. Power strips and smart plugs can also measure actual usage.
Does this include standby power?
No — this calculator assumes the appliance draws the stated wattage during active use only. Standby draw (phantom load) is typically 1–5 W per device.
Why does my bill differ from the estimate?
Actual bills include taxes, fees, tiered rates, and seasonal adjustments. This calculator gives a baseline estimate based on a flat per-kWh rate.