Energy & Power

Joules to Kilowatt-hours

Convert joules to kilowatt-hours instantly. 1 J = 2.77778e-07 kWh. Includes the exact factor, a conversion table of common values and the definition of both units.

J
Kilowatt-hours
One step, one exact factorJouleswhat you have× 2.77778e-07Kilowatt-hourswhat you getBoth units are defined against the same base unit, so the factor is exact — never an approximation.

How to convert joules to kilowatt-hours

To convert joules to kilowatt-hours, divide by 3600000.0000000005 (multiply by 2.77778e-07). The relationship is fixed, so the same factor works for any quantity — there is nothing to look up and nothing that changes with temperature, location or context.

kWh = J × 2.77778e-07

Joules to Kilowatt-hours conversion table

The values people look up most often, rounded for reading. Use the calculator above for anything in between.

JoulesKilowatt-hours
1 J2.778e-07 kWh
2 J5.556e-07 kWh
3 J8.333e-07 kWh
5 J1.389e-06 kWh
10 J2.778e-06 kWh
20 J5.556e-06 kWh
25 J6.944e-06 kWh
50 J1.389e-05 kWh
100 J2.778e-05 kWh
500 J0.0001389 kWh
1,000 J0.0002778 kWh

What is a joule?

The SI unit of energy: one newton-metre, or one watt for one second.

What is a kilowatt-hour?

The unit on every electricity bill: a thousand watts for one hour.

The formula

kWh = J × 2.77778e-07

Every result on this page comes from this formula. Nothing is rounded until the final display, so figures match a spreadsheet to the cent.

How to use the Joules to Kilowatt-hours

  1. Type the number of joules you want to convert.
  2. Read the result in kilowatt-hours straight away — there is no button to press.
  3. Check the table below for the values that come up most often, or reverse the conversion with the linked kilowatt-hours to joules page.

Joules to Kilowatt-hours — frequently asked questions

How many kilowatt-hours are in a joule?

One joule equals 2.77778e-07 kWh. kWh = J × 2.77778e-07

What is the formula to convert joules to kilowatt-hours?

The formula is kWh = J × 2.77778e-07. It is an exact definition rather than an approximation, so the conversion never drifts no matter how large the number.

How do I convert kilowatt-hours back to joules?

Divide instead of multiplying: one kilowatt-hour is 3600000.0000000005 J. The reverse converter is linked in the related tools list.

Is this conversion exact?

Yes. Both units are defined against the same base unit by international agreement, so the factor is exact — any rounding you see is only in the display, which you can widen by entering more decimal places.

Is this joules to kilowatt-hours free to use?

Yes. Every calculator on the site is free, needs no sign-up, and runs entirely in your browser, so your figures never leave your device.

What people search for

This page answers each of these searches. They are the exact phrases visitors use to find the joules to kilowatt-hours.

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About this calculator

Written and reviewed by The Samsung Calculator editorial team. Every calculator is written against a published formula, reviewed against at least one independent reference implementation, and dated when it changes.

Last reviewed August 19, 2026 · Calculation runs client-side · No data collected · Report an error