kWh Cost Calculator

Multiply the number of kWh by your rate per kWh. At $0.15 per kWh, 30 kWh costs 30 x 0.15 = $4.50. The calculator does this and rounds the answer to the nearest cent.

A kilowatt-hour is one kilowatt of power drawn for one hour. A 1000 watt heater run for one hour uses exactly 1 kWh, and the same heater run for 30 minutes uses 0.5 kWh.

When you tick daily usage, the yearly figure is the daily cost times 365 and the monthly figure is that yearly total divided by 12. Using 365 divided by 12 gives an average month of about 30.4 days rather than a calendar month.

It is on your electricity bill, often labelled as the energy charge, supply rate or price per unit. Divide the energy portion of the bill by the kWh used if it is not stated directly.

The results are formatted as US dollars, but the math is just amount times rate. Enter your rate in whatever currency you pay and read the number as that currency.

A typical home uses roughly 20 to 30 kWh per day, though it varies widely with home size, climate, heating type and appliances. Check a recent bill and divide the total kWh by the number of days it covers.

Bills often add fixed daily charges, delivery or network fees, taxes, tiered rates and time of use pricing. This tool covers the plain energy charge at one flat rate, so it is a floor rather than a full bill.

Both the energy and the rate must be greater than zero. A blank, zero or negative entry shows a prompt to enter a positive amount instead of a cost.

Yes. The calculation runs in your browser and nothing you enter is uploaded, so your usage and rate stay on your device.