Hartree to Millijoule Converter

Energy Converter

27 units available

Decimals:

From

To

4.359745e-15

1 Eh = 4.359745e-15 mJ

Formula:

mJ = Eh × 4.359745e-15

With your value: 1 Eh = 4.359745e-15 mJ

How big is that?

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

Your value1.00 Eh

Heartbeat (2.3e+17× your value)2.29e+17 Eh

AA battery charge (2.3e+21× your value)2.29e+21 Eh

Slice of bread (6.4e+22× your value)6.42e+22 Eh

Daily food intake (1.9e+24× your value)1.93e+24 Eh

Litre of petrol (7.8e+24× your value)7.84e+24 Eh

Other Hartree to Millijoule conversions

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

Hartree to Millijoule Conversion Table

Hartree (Eh)	Millijoule (mJ)
0.5	2.179872e-15
1	4.359745e-15
2	8.719489e-15
5	2.179872e-14
10	4.359745e-14
15	6.539617e-14
20	8.719489e-14
25	1.089936e-13
50	2.179872e-13
100	4.359745e-13
250	1.089936e-12
500	2.179872e-12
1000	4.359745e-12

Millijoule to Hartree Conversion Table

Millijoule (mJ)	Hartree (Eh)
0.5	1.146856e+14
1	2.293712e+14
2	4.587425e+14
5	1.146856e+15
10	2.293712e+15
15	3.440568e+15
20	4.587425e+15
25	5.734281e+15
50	1.146856e+16
100	2.293712e+16
250	5.734281e+16
500	1.146856e+17
1000	2.293712e+17

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.

Hartree (Eh)

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

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

How to Convert Hartree to Millijoule

To convert from Hartree (Eh) to Millijoule (mJ), multiply the value by 4.359745e-15.

Formula: mJ = Eh × 4.359745e-15

Reverse: Eh = mJ × 2.293712e+14

Step-by-Step Example

Start with your value in Hartree. For example: 5 Eh
Multiply by the conversion factor: 5 x 4.359745e-15
The result is: 2.179872e-14 mJ

About Hartree

The hartree (Eh) is a unit of energy and work. One hartree equals 4.359745 × 10^-18 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 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.

Frequently Asked Questions

How many Millijoule are in 1 Hartree?

There are exactly 4.359745e-15 Millijoule in 1 Hartree. This means the conversion factor from Hartree to Millijoule is 4.359745e-15.

What is the formula to convert Hartree to Millijoule?

The formula to convert Hartree to Millijoule is: mJ = Eh × 4.359745e-15. For example, to convert 10 Hartree to Millijoule, you would multiply 10 by 4.359745e-15.

What is a Hartree?