Electricity Cost Calculator
Estimate appliance electricity cost.
Input
Result
What is a Electricity Cost Calculator?
The Electricity Cost Calculator helps you calculate the cost of running electrical appliances based on wattage, usage time, and your electricity rate. Just enter your numbers and the tool does the rest — no manual math, no guesswork.
How to calculate Electricity Cost manually (the formula)
The specific formula depends on what you are calculating. The calculator applies the correct equation automatically, but understanding the formula helps you verify the results and adapt them to your own needs.
Example calculation
Enter your values into the calculator and it will produce an instant result. For a step-by-step walkthrough, try different inputs and observe how each one affects the outcome.
Common mistakes
- Forgetting to convert watts to kilowatts — Electricity is billed per kWh. Divide watts by 1000 first. A 100W bulb is 0.1 kW.
- Using incorrect time units — Hours must be in hours, not minutes. 30 minutes = 0.5 hours.
- Not including all appliances — Standby power (vampire draw) can account for 5–10% of your bill. Include devices that are always plugged in.
Frequently asked questions
How do I calculate electricity cost for an appliance?
Cost = (Wattage ÷ 1000) × Hours Used × Rate per kWh. A 1500W heater running 8 hours at 12¢/kWh costs $1.44.
What is a kilowatt-hour?
A kilowatt-hour (kWh) is 1000 watt-hours of energy. If you run a 1000W appliance for 1 hour, you use 1 kWh.
How do I find my electricity rate?
Check your utility bill. The average US residential rate is about 12–16 cents per kWh, but varies by state.
How much does it cost to run a 100W bulb?
A 100W bulb running 10 hours: (100 ÷ 1000) × 10 × $0.12 = $0.12 per day, or about $3.60 per month.
How can I reduce my electricity bill?
Use LED bulbs, unplug standby devices, run appliances during off-peak hours, and improve home insulation.
How do I calculate appliance energy consumption?
Energy (kWh) = Wattage ÷ 1000 × Hours. A 2000W AC running 6 hours uses (2000/1000) × 6 = 12 kWh per day.