Rydberg to Hartree Converter
Convert Rydberg (Ry) to Hartree (Eh) instantly. 1 Ry = 0.5 Eh.
Energy Converter
27 units available
1 Ry = 0.5 Eh
Formula:
Eh = Ry × 0.4999999172With your value: 1 Ry = 0.49999992 Eh
How big is that?
Everyday references on a logarithmic scale, all expressed in rydberg so you can sanity-check the result.
Other Rydberg to Hartree conversions
Rydberg to Hartree Conversion Table
| Rydberg (Ry) | Hartree (Eh) |
|---|---|
| 0.5 | 0.25 |
| 1 | 0.5 |
| 2 | 1 |
| 5 | 2.5 |
| 10 | 4.999999 |
| 15 | 7.499999 |
| 20 | 9.999998 |
| 25 | 12.499998 |
| 50 | 24.999996 |
| 100 | 49.999992 |
| 250 | 124.999979 |
| 500 | 249.999959 |
| 1000 | 499.999917 |
Hartree to Rydberg Conversion Table
| Hartree (Eh) | Rydberg (Ry) |
|---|---|
| 0.5 | 1 |
| 1 | 2 |
| 2 | 4.000001 |
| 5 | 10.000002 |
| 10 | 20.000003 |
| 15 | 30.000005 |
| 20 | 40.000007 |
| 25 | 50.000008 |
| 50 | 100.000017 |
| 100 | 200.000033 |
| 250 | 500.000083 |
| 500 | 1,000.000166 |
| 1000 | 2,000.000331 |
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.
Rydberg (Ry)
Energy
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
Hartree (Eh)
Energy
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 Rydberg to Hartree
To convert from Rydberg (Ry) to Hartree (Eh), multiply the value by 0.4999999172.
Formula: Eh = Ry × 0.4999999172
Reverse: Ry = Eh × 2.0000003313
Step-by-Step Example
- Start with your value in Rydberg. For example: 5 Ry
- Multiply by the conversion factor: 5 x 0.4999999172
- The result is: 2.5 Eh
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.
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.
Frequently Asked Questions
How many Hartree are in 1 Rydberg?
There are exactly 0.4999999172 Hartree in 1 Rydberg. This means the conversion factor from Rydberg to Hartree is 0.4999999172.
What is the formula to convert Rydberg to Hartree?
The formula to convert Rydberg to Hartree is: Eh = Ry × 0.4999999172. For example, to convert 10 Rydberg to Hartree, you would multiply 10 by 0.4999999172.
What is a 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.
What is a 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.
What are the common uses of Rydberg?
The Rydberg is commonly used in energy calculations, engineering and science, education.
Related Energy Conversions
Cite this page
UnitConvertLab. (2026). Rydberg to Hartree converter. UnitConvertLab. Retrieved from https://unitconvertlab.com/convert/rydberg-to-hartree