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Energy

Convert joules to kilowatt-hours

1 J=2.7778e-7kWh

Use the converter below to change any joules value into kilowatt-hours instantly — with formula, conversion table, and real-world examples.

2.7778e-7

Conversion formula

Forward
kilowatt-hours = joules × 2.7778e-7
Reverse
joules = kilowatt-hours × 3,600,000

Example: 10 J × 2.7778e-7 = 2.7778e-6 kWh.

About both units

From

Joule

J

The joule is the SI unit of energy, work and heat. Defined as one newton-metre or one watt-second. Named after James Prescott Joule who demonstrated the mechanical equivalent of heat. Lifting a 100 g apple 1 metre requires about 1 J.

Real-world: Lifting a 100 g apple 1 m: ≈ 1 J. 100 kcal snack: 418,400 J. Hand grenade: ~650 kJ.
Read full joule reference →
To

Kilowatt-Hour

kWh

The kilowatt-hour equals 3.6 megajoules — energy delivered by 1 kW for 1 hour. It is the standard unit on electricity bills worldwide. A UK home uses about 2900 kWh/year; an EV charge adds 10–80 kWh depending on battery.

Real-world: UK home: ~2900 kWh/year. Tesla Model 3 battery: 60–80 kWh. Typical EV efficiency: 15–20 kWh/100 km.
Read full kilowatt-hour reference →

Joule to Kilowatt-Hour conversion table

Common joules to kilowatt-hours values for quick reference.

Joule (J)Kilowatt-Hour (kWh)
1 J2.7778e-7 kWh
10 J2.7778e-6 kWh
100 J2.7778e-5 kWh
500 J0.0001389 kWh
1,000 J0.0002778 kWh
5,000 J0.001389 kWh
10,000 J0.002778 kWh
50,000 J0.01389 kWh
100,000 J0.02778 kWh
500,000 J0.1389 kWh

Tips & common mistakes

Quick tips

  • 1 J = 1 N·m = 1 W·s.
  • 1 kWh = 3,600,000 J (3.6 MJ).
  • For nutrition 1 kcal = 4.184 kJ.

Avoid these

  • Confusing joule (energy) with newton (force).
  • Mixing joule with watt — watt is joule per second.
  • Using kJ when labels call for kcal on US nutrition.

Frequently asked questions

How many kilowatt-hours in a joule?
One joule equals 2.7778e-7 kilowatt-hours.
How do I convert joules to kilowatt-hours?
Multiply the joule value by 2.7778e-7 to get the equivalent in kilowatt-hours.
What is 100 joules in kilowatt-hours?
100 joules equals 2.7778e-5 kilowatt-hours.
Is a joule bigger than a kilowatt-hour?
No. 1 joule equals 2.7778e-7 kilowatt-hours, so one joule is smaller.
How to convert joules to kilowatt-hours without a calculator?
Multiply by 0 for a quick estimate; use a calculator for precise results.

Related energy conversions

📊 See full comparison matrix →

More from Joule

J → kJ
1 = 0.001 kJ
J → MJ
1 = 1.0000e-6 MJ
J → Wh
1 = 0.0002778 Wh
J → cal
1 = 0.239 cal
J → kcal
1 = 0.000239 kcal
J → BTU
1 = 0.0009478 BTU
J → eV
1 = 6.2415e18 eV
J → thm
1 = 9.4782e-9 thm

More to Kilowatt-Hour

kJ → kWh
1 = 0.0002778 kWh
MJ → kWh
1 = 0.2778 kWh
Wh → kWh
1 = 0.001 kWh
cal → kWh
1 = 1.1622e-6 kWh
kcal → kWh
1 = 0.001162 kWh
BTU → kWh
1 = 0.0002931 kWh
eV → kWh
1 = 4.4505e-26 kWh
thm → kWh
1 = 29.3071 kWh

Conversions in other categories

WeightKilogram → PoundLengthKilometer → MileTemperatureCelsius → FahrenheitVolumeLiter → US GallonAreaSquare Meter → Square FootSpeedKilometer per Hour → Mile per HourPressureBar → Pound per Square InchPowerKilowatt → Mechanical Horsepower