Home & Apartment CalculatorsClient-Side Calculation Engine

Electricity Cost Calculator

Calculate electrical appliance power cost per month and year.

Home & Apartment Calculators

Electricity Cost Calculator

Calculate appliance power consumption in kWh and estimated monthly or annual electricity bill costs.

Daily Energy Cost
$1.80
12 kWh / day
Monthly Cost
$54.00 / month
360 kWh / month
Yearly Cost
$657.00 / year
4380 kWh / year

What is the Electricity Cost Calculator and How Does It Work?

The Electricity Cost Calculator estimates how much it costs to run any electrical appliance by converting its wattage and daily usage hours into kilowatt-hours (kWh), then multiplying by your local electricity rate.

Calculation Formula
Cost = (Watts ÷ 1000) × Hours per Day × Days × Cost per kWh

An appliance's power draw in watts is converted to kilowatts, multiplied by how many hours per day it runs, then multiplied by the number of days and your electricity rate to get total cost.

Where:
Watts= The appliance's power consumption rating
Hours/Day= How many hours per day the appliance runs
Cost per kWh= Your electricity rate, found on your utility bill
Worked Calculation Examples
Window Air Conditioner
Input:1000W, 8 hours/day, $0.15/kWh
Output:$36.00 / month

Daily kWh = (1000/1000)×8 = 8 kWh; monthly = 8×30 = 240 kWh; cost = 240×$0.15 = $36.00.

LED TV Left On
Input:100W, 5 hours/day, $0.15/kWh
Output:$2.25 / month

Daily kWh = (100/1000)×5 = 0.5 kWh; monthly = 0.5×30 = 15 kWh; cost = 15×$0.15 = $2.25.

Common Real-World Use Cases

Appliance Cost Comparison

Compare the running cost of different appliances (e.g. a space heater vs. central heating) before buying.

Energy Bill Troubleshooting

Identify which high-wattage appliances are driving up an unexpectedly high electricity bill.

Solar & Efficiency Planning

Estimate annual energy costs for appliances when planning a home energy audit or solar system size.

How to Use the Electricity Cost Calculator
  1. 1Enter the appliance's wattage (check the label or manual).
  2. 2Enter how many hours per day it typically runs.
  3. 3Enter your electricity rate per kWh from your utility bill.
  4. 4View the estimated daily, monthly, and yearly cost.
Pro Tips & Suggestions
  • •Your exact electricity rate is on your utility bill, usually listed as cents or dollars per kWh.
  • •For appliances with a range (like refrigerators that cycle on and off), use the average wattage from the appliance's energy guide label.
Common Mistakes to Avoid
  • •Leaving the Cost per kWh field blank or at 0. Unlike the wattage and hours fields, there's no built-in default rate (electricity prices vary too much by region to assume one) - if the rate is empty, the calculator will show a "valid" result of $0.00 rather than an error, which can look like a real answer instead of a missing input.

Frequently Asked Questions

Explore Category

Home & Apartment Calculators

Calculators for home projects, paint quantities, square footage, rent affordability, and room dimensions.

View All Category Tools

Related Calculators & Tools