Kilojoule to Rydberg Converter

Energy Converter

27 units available

Decimals:

From

To

4.587425e+20

1 kJ = 4.587425e+20 Ry

Formula:

Ry = kJ × 4.587425e+20

With your value: 1 kJ = 4.587425e+20 Ry

How big is that?

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

Heartbeat (1/1.0e+3 your value)0.00100 kJ

Your value1.00 kJ

AA battery charge (10× your value)10.0 kJ

Slice of bread (2.8e+2× your value)280 kJ

Daily food intake (8.4e+3× your value)8.40e+3 kJ

Litre of petrol (3.4e+4× your value)3.42e+4 kJ

Other Kilojoule to Rydberg conversions

2 kJ to Ry 3 kJ to Ry 4 kJ to Ry 5 kJ to Ry 6 kJ to Ry 7 kJ to Ry 8 kJ to Ry

Kilojoule to Rydberg Conversion Table

Kilojoule (kJ)	Rydberg (Ry)
0.5	2.293713e+20
1	4.587425e+20
2	9.174851e+20
5	2.293713e+21
10	4.587425e+21
15	6.881138e+21
20	9.174851e+21
25	1.146856e+22
50	2.293713e+22
100	4.587425e+22
250	1.146856e+23
500	2.293713e+23
1000	4.587425e+23

Rydberg to Kilojoule Conversion Table

Rydberg (Ry)	Kilojoule (kJ)
0.5	1.089936e-21
1	2.179872e-21
2	4.359744e-21
5	1.089936e-20
10	2.179872e-20
15	3.269808e-20
20	4.359744e-20
25	5.449680e-20
50	1.089936e-19
100	2.179872e-19
250	5.449680e-19
500	1.089936e-18
1000	2.179872e-18

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.

Kilojoule (kJ)

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

Rydberg (Ry)

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 Kilojoule to Rydberg

To convert from Kilojoule (kJ) to Rydberg (Ry), multiply the value by 4.587425e+20.

Formula: Ry = kJ × 4.587425e+20

Reverse: kJ = Ry × 2.179872e-21

Step-by-Step Example

Start with your value in Kilojoule. For example: 5 kJ
Multiply by the conversion factor: 5 x 4.587425e+20
The result is: 2.293713e+21 Ry

About Kilojoule

The kilojoule (kJ) is a unit of energy and work. One kilojoule equals 1000 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 Rydberg

The rydberg (Ry) is a unit of energy and work. One rydberg equals 2.179872 × 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.

Frequently Asked Questions

How many Rydberg are in 1 Kilojoule?

There are exactly 4.587425e+20 Rydberg in 1 Kilojoule. This means the conversion factor from Kilojoule to Rydberg is 4.587425e+20.

What is the formula to convert Kilojoule to Rydberg?

The formula to convert Kilojoule to Rydberg is: Ry = kJ × 4.587425e+20. For example, to convert 10 Kilojoule to Rydberg, you would multiply 10 by 4.587425e+20.

What is a Kilojoule?