Millijoule to Gigajoule Converter

Energy Converter

27 units available

Decimals:

From

To

1.000000e-12

1 mJ = 1.000000e-12 GJ

Formula:

GJ = mJ × 1.000000e-12

With your value: 1 mJ = 1.000000e-12 GJ

How big is that?

Everyday references on a logarithmic scale, all expressed in millijoule so you can sanity-check the result.

Your value1.00 mJ

Heartbeat (1.0e+3× your value)1.00e+3 mJ

AA battery charge (1.0e+7× your value)1.00e+7 mJ

Slice of bread (2.8e+8× your value)2.80e+8 mJ

Daily food intake (8.4e+9× your value)8.40e+9 mJ

Litre of petrol (3.4e+10× your value)3.42e+10 mJ

Other Millijoule to Gigajoule conversions

2 mJ to GJ 3 mJ to GJ 4 mJ to GJ 5 mJ to GJ 6 mJ to GJ 7 mJ to GJ 8 mJ to GJ

Millijoule to Gigajoule Conversion Table

Millijoule (mJ)	Gigajoule (GJ)
0.5	5.000000e-13
1	1.000000e-12
2	2.000000e-12
5	5.000000e-12
10	1.000000e-11
15	1.500000e-11
20	2.000000e-11
25	2.500000e-11
50	5.000000e-11
100	1.000000e-10
250	2.500000e-10
500	5.000000e-10
1000	1.000000e-9

Gigajoule to Millijoule Conversion Table

Gigajoule (GJ)	Millijoule (mJ)
0.5	500,000,000,000
1	1.000000e+12
2	2.000000e+12
5	5.000000e+12
10	1.000000e+13
15	1.500000e+13
20	2.000000e+13
25	2.500000e+13
50	5.000000e+13
100	1.000000e+14
250	2.500000e+14
500	5.000000e+14
1000	1.000000e+15

Where these values come from

Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.

Millijoule (mJ)

Energy

Exact conversion

Derived from the joule (1 J = 1 kg·m²/s²). Thermochemical and IT calories, BTU and kWh are exact defined multiples.

Source: NIST Special Publication 811, Guide for the Use of the International System of Units

National Institute of Standards and Technology (US) · Reviewed 2026-07-01

Gigajoule (GJ)

Energy

Exact conversion

Derived from the joule (1 J = 1 kg·m²/s²). Thermochemical and IT calories, BTU and kWh are exact defined multiples.

Source: NIST Special Publication 811, Guide for the Use of the International System of Units

National Institute of Standards and Technology (US) · Reviewed 2026-07-01

How to Convert Millijoule to Gigajoule

To convert from Millijoule (mJ) to Gigajoule (GJ), multiply the value by 1.000000e-12.

Formula: GJ = mJ × 1.000000e-12

Reverse: mJ = GJ × 1.000000e+12

Step-by-Step Example

Start with your value in Millijoule. For example: 5 mJ
Multiply by the conversion factor: 5 x 1.000000e-12
The result is: 5.000000e-12 GJ

About Millijoule

The millijoule (mJ) is a unit of energy and work. One millijoule equals 0.001 joules. UnitConvertLab converts it against every other energy unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: energy calculations, engineering and science, education.

About Gigajoule

The gigajoule (GJ) is a unit of energy and work. One gigajoule equals 1.000000 × 10^+9 joules. UnitConvertLab converts it against every other energy unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: energy calculations, engineering and science, education.

Frequently Asked Questions

How many Gigajoule are in 1 Millijoule?

There are exactly 1.000000e-12 Gigajoule in 1 Millijoule. This means the conversion factor from Millijoule to Gigajoule is 1.000000e-12.

What is the formula to convert Millijoule to Gigajoule?

The formula to convert Millijoule to Gigajoule is: GJ = mJ × 1.000000e-12. For example, to convert 10 Millijoule to Gigajoule, you would multiply 10 by 1.000000e-12.

What is a Millijoule?