Joules to kWh Converter

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Quick answer: To convert joules to kWh, multiply by 2.777778×10⁻⁷. For example, 10 J is 0.000002777778 kWh. One joule equals 2.777778×10⁻⁷ kWh.

Use the Joules to kWh Converter

Joules to kWh formula and what each symbol means

kWh = J × 2.777778×10⁻⁷

Symbols used in the formula
SymbolMeaning
JJoule
kWhKilowatt hour

Joules to kWh examples

1 J

1 J × 2.777778×10⁻⁷ = 2.777778×10⁻⁷ kWh.

10 J

10 J × 2.777778×10⁻⁷ = 0.000002777778 kWh.

100 J

100 J × 2.777778×10⁻⁷ = 0.00002777778 kWh.

Joules compared with kWh

One kWh is 3,600,000 times as large as one J, so your number gets smaller when you convert joules to kWh and bigger when you convert back. If the answer is not smaller than what you typed, you multiplied instead of dividing.

About joules and kWh

Joule (J): The SI unit of energy, one newton metre. Kilowatt hour (kWh): Energy used by a 1 kW device in one hour, exactly 3.6 MJ.

Where joules to kWh conversions are used

Gas and heating are often billed in therms, BTU or megajoules. Engineering and physics calculations usually work in joules.

How to calculate Joules to kWh step by step

  1. Enter the value in J (the starting unit).
  2. Multiply by 2.777778×10⁻⁷, because 1 J = 2.777778×10⁻⁷ kWh.
  3. The product is the value in kWh. To go back, divide by 2.777778×10⁻⁷ or multiply by 3,600,000.

Popular energy conversions

How to read your Joules to kWh result

Quick estimate: multiply by about 2.8×10⁻⁷ to get kWh from joules; this is within 0.8% of the exact factor. Food labels use the kilocalorie (kcal, written Calorie in the US), electricity bills use the kilowatt hour, and heating uses the Btu.

JOULESKWH
12.777778×10⁻⁷
25.555556×10⁻⁷
50.000001388889
100.000002777778
200.000005555556
500.00001388889
1000.00002777778
1,0000.0002777778

kWh to Joules: quick table

KWHJOULES
13,600,000
518,000,000
1036,000,000
2590,000,000
50180,000,000
100360,000,000
250900,000,000
5001,800,000,000

Common mistakes when calculating Joules to kWh

  • Confusing kW (power) with kWh (energy).
  • Dividing when you should multiply: from J to kWh multiply by 2.777778×10⁻⁷; from kWh to J divide by 2.777778×10⁻⁷.

Joules to kWh FAQ

How many kWh are in 1 J?

1 J equals 2.777778×10⁻⁷ kWh.

How many J are in 1 kWh?

1 kWh equals 3,600,000 J.

Is 1 J = 2.777778×10⁻⁷ kWh an exact conversion?

Yes. The joule and the kilowatt hour are both defined exactly in SI terms, so the ratio has no measurement uncertainty; 2.777778×10⁻⁷ is just that ratio shown to 7 significant figures.

What is a joule (J)?

The SI unit of energy, one newton metre.

How can I estimate joules to kWh in my head?

Quick estimate: multiply by about 2.8×10⁻⁷ to get kWh from joules; this is within 0.8% of the exact factor.

What is 7 J in kWh?

7 J = 0.000001944444 kWh (since 7 × 2.777778×10⁻⁷).

What is 40 J in kWh?

40 J = 0.00001111111 kWh (since 40 × 2.777778×10⁻⁷).

What is 200 J in kWh?

200 J = 0.00005555556 kWh (since 200 × 2.777778×10⁻⁷).

How many decimals should I keep when converting J to kWh?

Match the precision of your original measurement. For example, 0.000002777778 kWh rounds to 0.00000278 kWh at 3 significant figures; keep more digits only for engineering or scientific work.

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Method, review and disclaimer

Edited by: Hemant Kumar and Anjita Rai, founders of ToolsVault (SEO and content professional, not a licensed adviser). Method: this tool runs in your browser using the formula shown on this page; the numbers you enter are not sent to our servers. Sources: NIST SP 811, Appendix B.8: conversion factors