Convert Roentgen to Coulomb per Kilogram
Live bidirectional calculator for Roentgens (R) and Coulombs per Kilogram (C/kg) with verified formula and conversion charts.
Radiation Exposure3 units
How the Calculation Works (Linear Scaling)
Since 1 Coulomb per Kilogram = 3875.968992 Roentgens, divide the value in Roentgens by 3875.968992.
Roentgen to Coulomb per Kilogram Conversion Table
Precomputed values for quick reference and printing.
| Roentgen | Coulomb per Kilogram |
|---|---|
| 1 R | 0.0003 C/kg |
| 2 R | 0.0005 C/kg |
| 3 R | 0.0008 C/kg |
| 4 R | 0.001 C/kg |
| 5 R | 0.0013 C/kg |
| 6 R | 0.0015 C/kg |
| 7 R | 0.0018 C/kg |
| 8 R | 0.0021 C/kg |
| 9 R | 0.0023 C/kg |
| 10 R | 0.0026 C/kg |
| 15 R | 0.0039 C/kg |
| 20 R | 0.0052 C/kg |
| 25 R | 0.0064 C/kg |
| 30 R | 0.0077 C/kg |
| 40 R | 0.0103 C/kg |
| 50 R | 0.0129 C/kg |
| 75 R | 0.0193 C/kg |
| 100 R | 0.0258 C/kg |
| Coulomb per Kilogram | Roentgen |
|---|---|
| 1 C/kg | 3875.969 R |
| 2 C/kg | 7751.938 R |
| 3 C/kg | 11627.907 R |
| 4 C/kg | 15503.876 R |
| 5 C/kg | 19379.845 R |
| 6 C/kg | 23255.814 R |
| 7 C/kg | 27131.7829 R |
| 8 C/kg | 31007.7519 R |
| 9 C/kg | 34883.7209 R |
| 10 C/kg | 38759.6899 R |
| 15 C/kg | 58139.5349 R |
| 20 C/kg | 77519.3798 R |
| 25 C/kg | 96899.2248 R |
| 30 C/kg | 116279.0698 R |
| 40 C/kg | 155038.7597 R |
| 50 C/kg | 193798.4496 R |
| 75 C/kg | 290697.6744 R |
| 100 C/kg | 387596.8992 R |
π Standard Benchmark Reference Values
Exact international definition of ionizing radiation charge produced in 1 kg of dry air.
Exact RatioAbout Roentgen (R)
A legacy unit of radiation exposure defined as exactly 2.58 Γ 10β»β΄ coulombs per kilogram of air. Originally defined in 1928 as the amount of X-rays producing 1 esu of charge per 0.001293 g of air.
History: Named after Wilhelm Conrad RΓΆntgen, the discoverer of X-rays. Standardized by the ICRU in 1928 and legally redefined in SI units in 1971.
Common Uses: Survey meter calibration scales in the US, historical nuclear incident records (e.g. Chernobyl Geiger counter readings in R/h).
About Coulomb per Kilogram (C/kg)
The SI coherent derived unit of radiation exposure for ionizing radiation in air, representing the total electric charge of ions of one sign produced in 1 kilogram of dry air by X-rays or gamma rays (1 C/kg).
History: Adopted by the ICRU and BIPM to replace the legacy CGS roentgen with a coherent SI base quotient.
Common Uses: Ion chamber radiation calibration, medical X-ray machine exposure rate verification, health physics dosimetry.
β Frequently Asked Questions
How many Coulombs per Kilogram are in 1 Roentgen?
There are exactly 0.000258 Coulombs per Kilogram in 1 Roentgen (1 R = 0.000258 C/kg).
What is the formula to convert Roentgen to Coulomb per Kilogram?
The formula is: Coulomb per Kilogram = Roentgen / 3875.968992. Since 1 Coulomb per Kilogram = 3875.968992 Roentgens, divide the value in Roentgens by 3875.968992.
How do I convert 1 R to C/kg manually?
To convert 1 R to C/kg: apply the formula Coulomb per Kilogram = Roentgen / 3875.968992. Substituting gives: 1 / 3875.968992 = 0.0003 C/kg.