Electricity Cost Calculator
Calculate electricity cost from wattage, daily usage hours, and rate per kWh. See daily, weekly, monthly, and yearly costs. Free, 100% in your browser.
Reference
How is electricity cost calculated?
Electricity cost is based on energy consumption measured in kilowatt-hours (kWh). A kilowatt-hour is the energy used by a 1,000-watt appliance running for one hour. Your electric bill charges a rate per kWh (typically $0.10–$0.30 in the US), so knowing how many kWh an appliance uses lets you estimate its impact on your bill. This calculator projects costs across day, week, month, and year.
Electricity cost formula
kWh per day = (watts × hours per day) / 1000Daily cost = kWh per day × rate per kWhWeekly cost = daily cost × 7Monthly cost = daily cost × 30Yearly cost = daily cost × 365
Example: A 100W light bulb running 8 hours/day at $0.15/kWh:0.8 kWh/day × $0.15 = $0.12/day = $3.60/month = $43.80/year
Common use cases
- Appliance costs — find out how much your AC, heater, PC, or gaming console costs to run.
- Energy savings — compare costs of LED vs. incandescent bulbs, or old vs. new appliances.
- Mining rigs — calculate electricity cost for cryptocurrency mining hardware.
- Home office — estimate the electricity cost of running your work setup all day.
- Budget planning — understand which appliances drive your electric bill and where to cut costs.
Privacy
All calculations run 100% in your browser. No data is sent to any server.