How many kJ are in a kWh?

3,600 kilojoules make 1 kilowatt hour. Multiples follow directly: 2 kWh is 7,200 kJ and 0.5 kWh is 1,800 kJ. Press the swap button between the boxes to run the page that way round, with Kilowatt hour in the From box and Kilojoule in the To box.

What is the formula for kJ to kWh?

kWh = kJ / 3,600, and kJ = kWh x 3,600 in reverse. The 3,600 is not a measured constant: a watt is defined as a joule per second, an hour is 3,600 seconds, so a watt hour is 3,600 joules and a kilowatt hour is 3,600 kilojoules. That makes this conversion exact by definition rather than an approximation, however long the decimal turns out. Decimal-rational arithmetic preserves the written input and exact factors, then rounds the displayed and copied output to twelve significant digits when needed. kWh and kJ are energy units. There is no power or duration mode here; calculating power from energy requires a separately supplied duration.

Worked example: how many kWh is 10,000 kJ?

2.77777777778 kWh. Type 10,000 into the From box, with or without the commas, and 1e4 is read the same way. The list underneath restates it in the rest of the category, and at 100 kJ those rows read 100,000 J, 27.7777777778 Wh, 23,900.5736138 cal, 23.9005736138 kcal and 94.7817120313 BTU. Copy result copies the displayed headline without digit-grouping commas; each visible conversion row has its own Copy button. Displayed and copied values round to twelve significant digits. If native copying fails, a complete selectable summary identifies the input, selected pair and conventions and includes every unit in the category, including uncommon units.

Why is the answer a repeating decimal?

Because 1 divided by 3,600 does not terminate in base ten. One kilojoule is 0.000277777777778 kWh as the page prints it, with the sevens running to the 12 significant digits it keeps, and 1,000 kJ is 0.277777777778 kWh. The direction that does land clean is the other one, since any whole number of kilowatt hours is a whole number of kilojoules, and any multiple of 360 kJ is a clean answer too: 360 kJ is 0.1 kWh.

How do kilojoules relate to watt hours?

3.6 kJ is 1 Wh, so a kilojoule is 0.277777777778 Wh and 3,600 kJ is 1,000 Wh. The watt hour row sits in the list under the headline on every conversion, which is often the more readable unit for a battery or a small appliance figure, where a kilowatt hour answer would be a string of zeros after the point.

Which calorie and which BTU does the list use?

The calorie is thermochemical, exactly 4.184 J; its kilocalorie is exactly 4,184 J. Thus 1 kJ displays as 239.005736138 cal and 0.239005736138 kcal. The International Table calorie of exactly 4.1868 J is a separate definition absent from the menu. BTU uses the exact International Table value 1,055.05585262 J: 1 kJ displays as 0.947817120313 BTU and 1,000 kJ as 947.817120313 BTU. Check the source’s explicit calorie or BTU convention.

What is the electronvolt row for?

Show 1 more adds the electronvolt, defined here by exactly 1.602176634e-19 J. One kJ displays as 6.24150907446e21 eV. Displayed magnitudes at or above 1e15 or below 0.000001 use exponential notation, with the same twelve significant digits as decimal results.

Does converting kJ to kWh account for efficiency?

No. A kilojoule and a kilowatt hour are two names for the same amount of energy, and this page only changes the name. How much of that energy a motor, a heater or a charger actually delivers as useful work is a property of the machine, not of the units, so a conversion here is the input to that question rather than the answer to it. This focused page opens on Kilojoule and Kilowatt hour, while preserving the main converter’s saved unit pair. When storage is usable, a saved value and uncommon-unit preference can travel between pages. Its suffix must still match From. Valid deliberate scalar edits can save those fields after a short delay; invalid or incomplete drafts preserve the saved record. Unusable or conflicting records remain until you use Forget saved settings, which keeps the current conversion on screen. Your input and converted values are calculated in the browser and are not uploaded by the converter. The definitions arrive with the page, so conversion needs no external data lookup and keeps working offline after the page has loaded. The core conversion needs no account.

kJ to kWh Converter

A kilojoule and a kilowatt hour measure the same thing at very different scales: a watt is one joule per second, an hour is 3,600 seconds, and the kilo on each side cancels, so 3,600 kJ is exactly 1 kWh. This page opens with Kilojoule in the From box and Kilowatt hour in the To box, ahead of whatever pair the converter last remembered, so 100 kJ reads 0.0277777777778 kWh, 1,800 kJ reads 0.5 kWh and 36,000 kJ reads 10 kWh. Because 1/3,600 never terminates as a decimal, a single kilojoule prints as 0.000277777777778 kWh at the 12 significant digits the page carries, while the reverse multiplication by 3,600 produces a terminating decimal for a finite decimal input; either direction can need twelve-significant-digit display rounding. Under the headline the same energy appears in joules, watt hours, thermochemical calories, kilocalories and IT BTU at once, with the electronvolt held behind a Show 1 more switch, and the swap button turns the page into a kilowatt hours to kilojoules converter.

From

To0.000277777777778

Category: Energy

Base unit: joule

Uncommon units: Show 1 more

BTU uses the International Table definition (1,055.05585262 J); cal and kcal are thermochemical (4.184 J per cal). Wh and kWh are energy, not power in W or kW.

Results round to 12 significant digits using the listed unit definitions. Input must have a finite numeric magnitude and at most 512 significant digits. Type a single decimal or scientific number; a matching From unit suffix is accepted. Commas and grouped spaces separate thousands; decimal commas, fractions and compound measurements are refused.

1 kJ in every energy unit

JouleJ
1,000
Caloriecal
239.005736138
Kilocaloriekcal
0.239005736138
Watt hourWh
0.277777777778
Kilowatt hourkWh
0.000277777777778
British thermal unitBTU
0.947817120313

Selectable complete conversion

Unit Converter — Energy
Input: 1 (Kilojoule, kJ)
Result: 0.000277777777778 kWh (Kilowatt hour)
Displayed values round to 12 significant digits.
BTU uses the International Table definition (1,055.05585262 J); cal and kcal are thermochemical (4.184 J per cal). Wh and kWh are energy, not power in W or kW.
All other units:
Joule (J): 1000
Calorie (cal): 239.005736138
Kilocalorie (kcal): 0.239005736138
Watt hour (Wh): 0.277777777778
Kilowatt hour (kWh): 0.000277777777778
British thermal unit (BTU): 0.947817120313
Electronvolt (eV): 6.24150907446e21

Common questions

How many kJ are in a kWh?: 3,600 kilojoules make 1 kilowatt hour. Multiples follow directly: 2 kWh is 7,200 kJ and 0.5 kWh is 1,800 kJ. Press the swap button between the boxes to run the page that way round, with Kilowatt hour in the From box and Kilojoule in the To box.
What is the formula for kJ to kWh?: kWh = kJ / 3,600, and kJ = kWh x 3,600 in reverse. The 3,600 is not a measured constant: a watt is defined as a joule per second, an hour is 3,600 seconds, so a watt hour is 3,600 joules and a kilowatt hour is 3,600 kilojoules. That makes this conversion exact by definition rather than an approximation, however long the decimal turns out. Decimal-rational arithmetic preserves the written input and exact factors, then rounds the displayed and copied output to twelve significant digits when needed. kWh and kJ are energy units. There is no power or duration mode here; calculating power from energy requires a separately supplied duration.
Worked example: how many kWh is 10,000 kJ?: 2.77777777778 kWh. Type 10,000 into the From box, with or without the commas, and 1e4 is read the same way. The list underneath restates it in the rest of the category, and at 100 kJ those rows read 100,000 J, 27.7777777778 Wh, 23,900.5736138 cal, 23.9005736138 kcal and 94.7817120313 BTU. Copy result copies the displayed headline without digit-grouping commas; each visible conversion row has its own Copy button. Displayed and copied values round to twelve significant digits. If native copying fails, a complete selectable summary identifies the input, selected pair and conventions and includes every unit in the category, including uncommon units.
Why is the answer a repeating decimal?: Because 1 divided by 3,600 does not terminate in base ten. One kilojoule is 0.000277777777778 kWh as the page prints it, with the sevens running to the 12 significant digits it keeps, and 1,000 kJ is 0.277777777778 kWh. The direction that does land clean is the other one, since any whole number of kilowatt hours is a whole number of kilojoules, and any multiple of 360 kJ is a clean answer too: 360 kJ is 0.1 kWh.
How do kilojoules relate to watt hours?: 3.6 kJ is 1 Wh, so a kilojoule is 0.277777777778 Wh and 3,600 kJ is 1,000 Wh. The watt hour row sits in the list under the headline on every conversion, which is often the more readable unit for a battery or a small appliance figure, where a kilowatt hour answer would be a string of zeros after the point.
Which calorie and which BTU does the list use?: The calorie is thermochemical, exactly 4.184 J; its kilocalorie is exactly 4,184 J. Thus 1 kJ displays as 239.005736138 cal and 0.239005736138 kcal. The International Table calorie of exactly 4.1868 J is a separate definition absent from the menu. BTU uses the exact International Table value 1,055.05585262 J: 1 kJ displays as 0.947817120313 BTU and 1,000 kJ as 947.817120313 BTU. Check the source’s explicit calorie or BTU convention.
What is the electronvolt row for?: Show 1 more adds the electronvolt, defined here by exactly 1.602176634e-19 J. One kJ displays as 6.24150907446e21 eV. Displayed magnitudes at or above 1e15 or below 0.000001 use exponential notation, with the same twelve significant digits as decimal results.
Does converting kJ to kWh account for efficiency?: No. A kilojoule and a kilowatt hour are two names for the same amount of energy, and this page only changes the name. How much of that energy a motor, a heater or a charger actually delivers as useful work is a property of the machine, not of the units, so a conversion here is the input to that question rather than the answer to it. This focused page opens on Kilojoule and Kilowatt hour, while preserving the main converter’s saved unit pair. When storage is usable, a saved value and uncommon-unit preference can travel between pages. Its suffix must still match From. Valid deliberate scalar edits can save those fields after a short delay; invalid or incomplete drafts preserve the saved record. Unusable or conflicting records remain until you use Forget saved settings, which keeps the current conversion on screen. Your input and converted values are calculated in the browser and are not uploaded by the converter. The definitions arrive with the page, so conversion needs no external data lookup and keeps working offline after the page has loaded. The core conversion needs no account.

Results round to 12 significant digits using the listed unit conventions. Many factors are exact definitions; psi and parsec use rounded coefficients. Temperature includes scale offsets. Days and weeks are fixed-duration units, and unit conversion does not determine calendar dates, ambient pressure or a software label’s convention.