⚡ Every time you turn on a light, run the AC, or charge your phone, you’re using electricity — and paying for it. But how much does it actually cost? Knowing how to calculate kilowatt-hour (kWh) cost helps you take control of your energy bills and make smarter power usage decisions.
In this article, we’ll explain what kWh means, how to calculate the cost of your electricity usage, and include a handy calculator to make it easy.
Table of Contents
💡 What Is a kWh?
A kilowatt-hour (kWh) is a unit of energy that measures how much electricity you use over time.
- 1 kWh = using 1,000 watts for 1 hour
So if you run a 1,500-watt heater for 2 hours, you’ve used:
1.5 kW × 2 hours = 3 kWh
Your electricity bill is based on the total number of kWh consumed multiplied by the rate your utility provider charges.
Use the calculator below to estimate the cost of running any electrical appliance based on its wattage, usage time, and your local electricity rate:
📚 Formula to Calculate kWh Cost
To calculate the cost of running any electrical device, use this formula:
kWh Cost = (Wattage × Hours Used ÷ 1,000) × Cost per kWhWhere:
- Wattage = power of the appliance in watts
- Hours Used = total time it runs
- Cost per kWh = rate charged by your electricity provider (e.g., $0.15)
📊 Example Calculation
Let’s say you run a 1,200-watt space heater for 3 hours per day, and your utility rate is $0.18 per kWh.
Step 1:
1,200 W × 3 hours = 3,600 Wh = 3.6 kWh
Step 2:
3.6 kWh × $0.18 = $0.65 per day
That one heater could cost around $19.44 per month!
💡 Final Thoughts
Learning how to calculate kWh cost helps you make informed energy choices and lower your electricity bill. Use the calculator above to test different appliances and usage times — the savings might surprise you!