UtilityBaseCalculators
Electricity Cost Calculator
Estimate what a device costs to run from its wattage, hours, and your kWh rate.
Updated July 13, 2026
How to use the electricity cost calculator
- 1Enter the device's power in watts, or pick one from the appliance list.
- 2Enter how many hours a day it runs (use effective run-time for cycling devices).
- 3Enter your electricity rate in dollars per kWh from a recent bill.
- 4Read the cost per day, month, and year.
Common uses
- Seeing what a space heater or AC adds to the winter or summer bill
- Estimating the yearly cost of an always-on device like a PC or fridge
- Deciding whether an old appliance is worth replacing
- Budgeting the cost of charging an EV at home
Frequently asked questions
How is the running cost calculated?
Cost = watts ÷ 1000 × hours × rate. Dividing watts by 1000 gives kilowatts; multiplying by hours gives kilowatt-hours (kWh), the unit you're billed in; multiplying by your rate gives the cost. A 1500 W heater for 3 hours at $0.17/kWh costs 1.5 × 3 × 0.17 ≈ $0.77 a day.
Where do I find a device's wattage?
Check the label or nameplate on the device or its power supply — it lists watts (W), or the volts and amps you can multiply (V × A ≈ W). The appliance presets here are rough averages; use your device's actual figure for accuracy, and remember many appliances cycle on and off rather than drawing full power continuously.
What electricity rate should I use?
Use the rate from a recent bill — total cost divided by kWh used, including delivery charges. The US residential average is around $0.17/kWh but ranges from under $0.11 to over $0.40 by state, and some plans charge more at peak hours. Enter your real rate for the most accurate result.
About this tool
The electricity cost calculator estimates the running cost of any appliance from three numbers: its power in watts, how many hours a day you use it, and your electricity rate per kilowatt-hour. It works out the energy used and the cost per day, month, and year, so you can see what that space heater, gaming PC, or always-on device is really adding to the bill. A dropdown loads typical wattages for common appliances to get you started, and the math is the standard watts ÷ 1000 × hours × rate. Everything runs in your browser.
Like most tools on UtilityBase, the electricity cost calculator runs entirely in your browser — nothing you enter is uploaded or stored on a server. It's free to use with no account required. Browse more calculators here.
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