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kWh Cost Calculator

A kWh cost calculator tells you what an appliance actually costs to run — per day, month and year — from its wattage, how long you use it, and your electricity rate. It turns a sticker wattage into real money, which is how you decide whether something is worth running or replacing.

Your measurements

Result

Enter the watts (off the label or a plug-in meter), the daily hours and your rate per kWh, and it does the arithmetic in your own currency.

How it is calculated

Energy (kWh) = watts ÷ 1000 × hours. Cost = energy × your rate per kWh. Monthly and yearly figures scale by days. Rates vary widely by region and time-of-use plan, so use your actual bill rate. Cycling appliances (fridges, AC, heaters) should use average daily run-hours, not nameplate-on time.

Steps

Enter the device's power in watts (label or a plug-in meter).
Enter how many hours a day you use it.
Enter your electricity rate per kWh (from your bill).
Read the cost per day, month and year.
For appliances that cycle on/off, use average run-hours.

Worked example

A 1,000 W device run 5 hours a day at $0.17/kWh costs about $0.85 a day — roughly $25.50 a month, or $310 a year.

Common questions

How do I calculate the cost to run an appliance?

Watts ÷ 1000 × hours × your rate per kWh. A 1,000 W device for 5 hours at 17 cents is about 85 cents a day.

Where do I find my electricity rate?

On your power bill, as a price per kWh. Many plans vary by time of day — use your average or peak rate.

What uses the most electricity at home?

Heating, cooling, water heating and anything resistive (heaters, dryers). Run those through the calculator to see the yearly cost.

Is it cheaper to replace an old appliance?

Sometimes — compare the yearly running cost here against a new efficient model's. Big savings often pay back the purchase.