MultiConvers

kWh Cost Calculator

Multiply kilowatt-hours you already know by the unit price on your tariff. No watts, no hours, no appliance schedule — just cost = kWh × rate. Twelve kilowatt-hours at 0.25 is 3.00 in whatever currency you used for the price.

Updated

How to use

  1. Enter energy in kWh from a meter, an EV session readout, or a bill line.
  2. Enter the unit price per kWh (the energy rate, not the standing charge).
  3. Read total cost to two decimals. 10 kWh at 0.20 is 2.00.
  4. If you only have watts and hours, use Electricity Cost first. If you have daily hours over a month, use Appliance Energy Cost.

How it works

A kilowatt-hour is one kilowatt running for one hour, or any equivalent pair (500 W for two hours, 2 kW for 30 minutes). Once someone else has already turned that into kWh, the money question is a product. This page exists for that last step: a charger that says “12 kWh delivered,” a smart-meter increment, a solar export line you want to value at a feed-in rate.

It will not turn a 2,200 W kettle into kWh. Electricity Cost does power × hours. Appliance Energy Cost repeats hours per day and days per month. EV Charging Cost starts from battery percent and efficiency, then multiplies grid kWh by price — a longer path to a similar last multiply.

Standing charges, taxes, capacity fees and time-of-use bands are omitted. If you have a day rate and a night rate, run the day kWh at one price and the night kWh at the other, then add. Using the average of the whole bill as “price per kWh” folds standing charges into a session that did not cause them.

Negative energy or negative price is rejected. Zero energy or zero price yields zero cost, which is a valid “free night rate” check. Currency is whatever you typed; the result is not converted.

This is not a utility bill and not a meter. It is the identity printed on every tariff sheet: energy times unit rate.

Formula

Cost = kWh × price per kWh

Worked examples

  • A 12 kWh session

    12 kWh at 0.25 / kWh → 3.00

  • A round 10 kWh

    10 kWh at 0.20 / kWh → 2.00

Useful notes

  • No standing charge, tax or time-of-use split.
  • Negative energy or price is rejected.
  • Does not convert watts and hours — start from kWh you already have.

FAQ

What is a kWh?

One kilowatt running for one hour, or any equivalent (500 W for two hours, and so on).

Where do I find my price per kWh?

On your electricity bill or tariff sheet. Use the unit rate, not the standing charge.

How is this different from the electricity cost tool?

This starts from kWh you already know. The other starts from watts or kW and hours.

Can I value solar export with this?

Yes, if you enter exported kWh and the feed-in price per kWh. It is still a product, not a full FIT statement.

Should I include VAT in the price?

Use the rate that matches the cost you want. If the bill’s unit rate is VAT-inclusive, enter that; the page does not add tax.

Guides

Related tools

See all Energy tools.

Sources