kj to wh | Exact Decimal + Formula

1 Kilojoule = 0.277778 Watt-hour

One watt-hour equals about 3.6 kilojoules (exactly 3.6 kJ). Real-world use: food-energy labels in many countries and technical energy measurements. This page expresses those values in watt-hours, which is used for battery capacities and small appliance energy consumption. Enter any value above — the result updates instantly, and a 1–1000 reference table follows below.

About Kilojoule and Watt-hour

Kilojoule (kJ)

A kilojoule is 1,000 joules.

Where it's used: Food-energy labels in many countries and technical energy measurements.

Watt-hour (Wh)

A watt-hour is one watt of power sustained for one hour, equal to 3,600 joules.

Where it's used: Battery capacities and small appliance energy consumption.

Energy Converter

From

Tab Switch fieldsS SwapC Copy

Precision

Formula

Wh = kJ × 0.277777778

To convert Kilojoule to Watt-hour, use the formula displayed above.

Pinned Favorites

No pinned converters yet. Click the star button to pin common pairs.

Recent History

Conversions you copy will be recorded here.

Kilojoule to Watt-hour: Quick Reference Table

Kilojoule	Watt-hour (Decimal)	Fraction	Real-world equivalent
0.001 kJ	0.000278 Wh	-	fractional unit measurement
0.01 kJ	0.002778 Wh	-	fractional unit measurement
0.1 kJ	0.027778 Wh	-	fractional unit measurement
0.5 kJ	0.138889 Wh	-	fractional unit measurement
1 kJ	0.277778 Wh	-	fractional unit measurement
2 kJ	0.555556 Wh	-	fractional unit measurement
5 kJ	1.388889 Wh	-	standard single unit scale
10 kJ	2.777778 Wh	-	standard single unit scale
25 kJ	6.944444 Wh	-	standard single unit scale
50 kJ	13.888889 Wh	-	multiple unit increments
100 kJ	27.777778 Wh	-	multiple unit increments
250 kJ	69.444444 Wh	-	multiple unit increments
500 kJ	138.888889 Wh	-	multiple unit increments
1000 kJ	277.777778 Wh	-	multiple unit increments

kJ to Wh Formula and Examples

Direct Formula Wh = kJ × 0.277777778

Inverse Formula kJ = Wh × 3.6

Mental Math Shortcut

Divide the value by roughly 3.6 to quickly estimate the converted result.

Common Kilojoule to Watt-hour Calculations

5 kJ = 1.388889 Wh
10 kJ = 2.777778 Wh
50 kJ = 13.888889 Wh
100 kJ = 27.777778 Wh
500 kJ = 138.888889 Wh

Precision & Practical Use

For example, 10 kJ = 2.777778 Wh — roughly standard single unit scale.

Utility bills and appliance ratings are given in whole kWh or BTU. Round converted figures to match the source document you're comparing against.

How to Convert Kilojoule to Watt-hour

How many watt-hours are in one kilojoule?

One Kilojoule (kJ) equals 0.277778 Watt-hour (Wh). To convert kilojoules to watt-hours, multiply the kilojoule value by 0.277778.

How do I convert Kilojoule to Watt-hour?

Multiply your kilojoule value by 0.277778 to get the result in Watt-hour: Wh = kJ × 0.277778. For example, 5 kJ = 1.388889 Wh.

What is the formula for converting kJ to Wh?

The conversion formula is Wh = kJ × 0.277778. Use the calculator above for any value, and see the reference table below for common inputs from 0.001 to 1000.

Is there a quick mental estimate for kJ to Wh?