Convert 20 Hartree (Eh) to Millijoule (mJ).

20 Hartree equals 8.719489e-14 Millijoule. Multiply 20 by 4.359745e-15.

What is 20 Hartree in Millijoule?

20 Hartree equals 8.719489e-14 Millijoule.

How many Millijoules are in 1 Hartree?

There are exactly 4.359745e-15 Millijoules 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 Hartrees to Millijoules, you would multiply 10 by 4.359745e-15.

What are the common uses of Hartree?

The Hartree is commonly used in energy calculations, engineering and science, education.

What is 20 Hartree in Millijoule?

To convert 20 Hartrees to Millijoules, multiply by 4.359745e-15. Therefore, 20 Hartree (Eh) equals 8.719489e-14 Millijoule (mJ).

20 Hartree = 8.719489e-14 Millijoule

Worked example: converting Hartree to Millijoule

Step 1 — start with the formula. mJ = Eh × 4.359745e-15
Step 2 — substitute your figure. 20 Eh × 4.359745e-15
Step 3 — read the result. 20 Eh = 8.719489e-14 mJ
Step 4 — check it in reverse. Eh = mJ × 2.293712e+14 returns 20 Eh, which matches the figure you started with.

Energy Converter

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Decimals:

From

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8.719489e-14

20 Eh = 8.719489e-14 mJ

Formula:

mJ = Eh × 4.359745e-15

With your value: 20 Eh = 8.719489e-14 mJ

How big is that?

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

Your value20.0 Eh

Heartbeat (1.1e+16× your value)2.29e+17 Eh

AA battery charge (1.1e+20× your value)2.29e+21 Eh

Slice of bread (3.2e+21× your value)6.42e+22 Eh

Daily food intake (9.6e+22× your value)1.93e+24 Eh

Litre of petrol (3.9e+23× your value)7.84e+24 Eh

Other Hartree to Millijoule conversions

14 Eh to mJ 15 Eh to mJ 16 Eh to mJ 18 Eh to mJ 21 Eh to mJ 24 Eh to mJ 25 Eh to mJ Full Hartree to Millijoule converter

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

Hartree and Millijoule Relationship

This calculation facilitates standardized conversion between recognized units of energy. Since 1 Hartree represents a fraction of a Millijoule (1 Millijoule ≈ 2.294e+14 Hartrees), the Millijoule is the larger measurement interval. Understanding the relationship between Hartree and Millijoule is essential for accurate calculations in physics, engineering, commerce, and daily applications.

About Hartree

The Hartree (symbol: Eh) is a recognized unit in the Standard measurement framework, utilized within energy applications for precision and standardized data representation.

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

About Millijoule

The Millijoule (symbol: mJ) is a recognized unit in the Metric (SI) measurement framework, utilized within energy applications for precision and standardized data representation.

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

Frequently Asked Questions

What is 20 Hartree in Millijoule?: 20 Hartree equals 8.719489e-14 Millijoule.
How many Millijoules are in 1 Hartree?: There are exactly 4.359745e-15 Millijoules 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 Hartrees to Millijoules, you would multiply 10 by 4.359745e-15.
What is a Hartree?: The Hartree (symbol: Eh) is a recognized unit in the Standard measurement framework, utilized within energy applications for precision and standardized data representation.
What is a Millijoule?: The Millijoule (symbol: mJ) is a recognized unit in the Metric (SI) measurement framework, utilized within energy applications for precision and standardized data representation.
What are the common uses of Hartree?: The Hartree is commonly used in energy calculations, engineering and science, education.

20 Hartree to Millijoule

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