Electricity Cost Calculator
Type in an appliance's wattage and how you use it, and see exactly what it costs to run each day, month, and year.
📖 How it works & FAQWhat this calculator tells you
Every electric device has a power rating in watts, printed on a label or in its manual. This tool turns that number into real money by combining it with how long you run the device and what your utility charges per kilowatt-hour (kWh). The result is the true running cost of a space heater, air conditioner, dryer, gaming PC, pool pump, or anything else that plugs in.
The math is simple and transparent: cost = watts ÷ 1000 × hours per day × days × rate. Dividing watts by 1000 converts to kilowatts, multiplying by hours gives kilowatt-hours, and multiplying by your rate gives dollars. We show it over one day, 30 days, and 365 days so you can see the small daily number add up.
Finding your numbers
Watts are usually on a nameplate near the power cord or in the specs. If you only see amps, multiply amps by volts (120 in the US) to get watts. Your rate in dollars per kWh is on your electric bill; the US average is roughly $0.17, but yours may be higher or lower depending on your region and time of use.
How to use it
- Enter the device's power draw in watts.
- Enter how many hours per day you actually run it.
- Enter your electricity rate in dollars per kWh from your latest bill.
- Read the daily, monthly, and yearly cost and kWh, updated instantly.
These figures are estimates for planning and comparison, not professional energy or financial advice.
FAQ
- Where do I find a device's wattage?
- Check the label near the plug, the user manual, or the manufacturer's website. If only amps are listed, multiply amps by your outlet voltage (usually 120V in the US, 230V in much of Europe).
- Why do the monthly and yearly numbers use 30 and 365 days?
- We scale your daily cost by 30 days for a month and 365 days for a year so the estimates stay consistent and easy to compare across devices.
- Does this include standby or "phantom" power?
- No. It only counts the hours you enter. If a device also draws power in standby, add those hours at its lower standby wattage for a fuller picture.
- What is a typical electricity rate?
- US residential rates average around $0.17 per kWh but range widely. Use the exact rate from your bill for the most accurate result.