Gigajoules to Kilojoules Converter — GJ to kJ

Convert Gigajoule (GJ) to Kilojoule (kJ) using the exact conversion factor (1 gigajoule = 1,000,000 kilojoule). See the formula, worked examples, and conversion table.

Gigajoules to Kilojoules converter

Converter

Energy Converter

Convert joules, calories, kilowatt-hours, BTU, electronvolts, therms, and mechanical work units.

Result 1 gigajoule = 1,000,000 kilojoule
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From definition

Gigajoule is 1000000000 joule units.

To definition

Kilojoule is 1000 joule units.

Formula

Result = input x 1e+9 / 1000.

Energy uses the joule as the base unit.

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About Converting Gigajoules to Kilojoules

Gigajoule and Kilojoule both measure energy, and the conversion is especially useful for comparing nutrition labels (kilocalories) against scientific energy figures (joules). Specifically: Gigajoule is 1000000000 joule units, and kilojoule is 1000 joule units.

Formula

kilojoules = gigajoules × 1000000

This factor comes from each unit's defined relationship to the category's base unit: 1 gigajoule equals 1000000000 base units, and 1 kilojoule equals 1000 base units, so dividing one by the other gives the direct gigajoule-to-kilojoule factor of 1000000.

Simple example

1 GJ × 1000000 = 1,000,000 kJ

1 gigajoule = 1,000,000 kilojoules.

Real-world example

100 GJ × 1000000 = 100,000,000 kJ

100 gigajoules = 100,000,000 kilojoules.

Conversion table

Gigajoule (GJ)Kilojoule (kJ)
1 GJ1,000,000 kJ
10 GJ10,000,000 kJ
100 GJ100,000,000 kJ
500 GJ500,000,000 kJ
1,000 GJ1,000,000,000 kJ
2,000 GJ2,000,000,000 kJ

Reverse conversion: Kilojoule to Gigajoule

1 kJ × 0.000001 = 0.000001 GJ

1 kilojoule = 0.000001 gigajoules.

gigajoules = kilojoules × 0.000001

For a page dedicated to this direction, see Kilojoule to Gigajoule.

Understanding the Gigajoule (GJ)

Gigajoule is 1000000000 joule units.

Understanding the Kilojoule (kJ)

Kilojoule is 1000 joule units.

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Frequently asked questions

How many kilojoules are in 1 gigajoule?

1 gigajoule equals 1,000,000 kilojoules, using the exact defined conversion factor rather than an estimate.

How do I convert gigajoule to kilojoule?

Multiply the gigajoule value by 1000000. The converter above does this instantly to whatever precision you set.

How do I convert kilojoule back to gigajoule?

Use the reverse factor: 1 kilojoule equals 0.000001 gigajoules. You can also use the swap control in the converter above to flip the direction instantly.

What is a gigajoule?

Gigajoule (GJ) is a unit of energy.

What is a kilojoule?

Kilojoule (kJ) is a unit of energy.

Is the gigajoule to kilojoule conversion exact?

Yes. Both gigajoule and kilojoule are defined by fixed standards rather than physical artifacts, so the factor of 1000000 used above is exact to as many digits as you choose to display.