Every electrical appliance in your home uses energy, but it can be difficult to know how much each appliance actually costs to run.
A refrigerator may operate throughout the day, an air conditioner may run for several hours, while a kettle may be used for only a few minutes. Their electricity costs depend mainly on power consumption, operating time, and your electricity rate.
An Electricity Cost Calculator makes it easier to estimate how much individual appliances cost to run based on their wattage, usage time and electricity rate.
An Electricity Cost Calculator makes it easy to estimate the energy used by an appliance and its approximate running cost.
For example, if a 1,000-watt appliance runs for 2 hours, it consumes:
1,000 W × 2 hours = 2,000 Wh
Since:
1,000 Wh = 1 kWh
the appliance uses:
2 kWh
If electricity costs $0.20 per kWh:
2 × $0.20 = $0.40
So the estimated electricity cost is:
$0.40
What Is a Kilowatt-Hour (kWh)?
Electricity consumption is commonly measured in kilowatt-hours, abbreviated as kWh.
A kilowatt equals:
1 kilowatt = 1,000 watts
A kilowatt-hour represents using 1,000 watts of power for one hour.
For example:
1,000 W × 1 hour = 1 kWh
Similarly:
500 W × 2 hours = 1 kWh
and:
100 W × 10 hours = 1 kWh
This is why both an appliance’s wattage and how long it operates matter.
Electricity Consumption Formula
To calculate energy consumption:
Energy (kWh) = Power (Watts) × Hours Used ÷ 1,000
For example, suppose a 1,500-watt heater operates for 3 hours.
1,500 × 3 ÷ 1,000 = 4.5 kWh
The heater therefore consumes approximately:
4.5 kWh
Electricity Cost Formula
Once you know the energy consumption, calculate the cost with:
Electricity Cost = Energy Used (kWh) × Electricity Rate per kWh
Suppose the rate is:
$0.20 per kWh
Then:
4.5 × $0.20 = $0.90
Estimated cost:
$0.90
Example 1 — Television
Suppose a television uses 120 watts and operates for 5 hours per day.
Energy:
120 × 5 ÷ 1,000 = 0.6 kWh/day
At $0.20 per kWh:
0.6 × $0.20 = $0.12/day
For 30 days:
$0.12 × 30 = $3.60/month
Estimated monthly cost:
$3.60
Example 2 — Electric Heater
Power:
1,500 watts
Usage:
4 hours/day
Energy:
1,500 × 4 ÷ 1,000 = 6 kWh/day
At $0.20/kWh:
6 × $0.20 = $1.20/day
For 30 days:
$1.20 × 30 = $36.00/month
Estimated monthly cost:
$36.00
Example 3 — Air Conditioner
Suppose an air conditioner draws 1,200 watts while running for an illustrative 8 hours per day.
Energy:
1,200 × 8 ÷ 1,000 = 9.6 kWh/day
At $0.20/kWh:
9.6 × $0.20 = $1.92/day
For 30 days:
$1.92 × 30 = $57.60/month
Estimated monthly cost:
$57.60
Actual consumption can vary because many appliances cycle on and off rather than continuously drawing their rated power.
Daily, Monthly and Yearly Electricity Cost
Once you know the daily cost, you can estimate longer periods.
Monthly Cost = Daily Cost × Number of Days
Yearly Cost = Daily Cost × 365
For example, if an appliance costs approximately:
$0.50/day
then:
30-day estimate = $15
and:
365-day estimate = $182.50
These estimates can help you compare appliances and identify opportunities to reduce energy use.
Watts vs Kilowatts
Remember:
1,000 watts = 1 kilowatt
Therefore:
500 W = 0.5 kW
1,500 W = 1.5 kW
2,000 W = 2 kW
When calculating kWh, convert watts to kilowatts by dividing by 1,000.
Where Can You Find Appliance Wattage?
For additional guidance on appliance energy use and operating costs, see the U.S. Department of Energy Energy Saver Guide.
The wattage may appear on:
🏷️ The appliance label
📘 Product manual
🔌 Power adapter
📦 Product packaging
🌐 Manufacturer specifications
Some appliances display watts directly, while others provide electrical ratings from which power may be estimated.
Why Calculate Electricity Costs?
Knowing approximate appliance running costs can help you:
💡 Understand energy consumption
💰 Estimate electricity expenses
🏠 Compare household appliances
❄️ Evaluate air-conditioning costs
🔥 Estimate heater running costs
📊 Plan household budgets
🌱 Identify opportunities to reduce energy use
Important: Electricity Rates Vary
Electricity prices are not the same everywhere.
Rates may vary according to country, utility provider, tariff, consumption level, taxes, fees, or time of use.
Therefore, for the best estimate, enter the actual electricity rate shown on your bill rather than relying on a generic rate.
The calculator provides an estimate, and the final utility bill may include additional charges.
How to Use the Electricity Cost Calculator
1. Enter the appliance wattage.
2. Enter how many hours it operates.
3. Enter your electricity rate per kWh.
4. Choose the usage period if your calculator provides this option.
5. Click Calculate.
The calculator can then estimate the appliance’s energy consumption and electricity cost.
Calculate Your Electricity Cost
Want to know approximately how much your appliances cost to operate?
Use our Electricity Cost Calculator to compare appliance costs and better understand your daily, monthly and yearly electricity expenses.
Enter the appliance’s power, usage time, and your local electricity rate into our Electricity Cost Calculator.
👉 Use the Electricity Cost Calculator
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