Convert Coulombs per kilogram to Roentgens
Convert Coulombs per kilogram (C/kg) to Roentgens (R) instantly and accurately.
Conversion Formula
R = C/kg × 3875.968992
About Coulombs per kilogram
The coulomb per kilogram (C/kg) is the SI derived unit of radiation exposure, equal to 1 coulomb of ion charge liberated per kilogram of dry air. It replaced the roentgen in SI. Calibration of clinical X-ray beams with free-air ionisation chambers and parallel-plate chambers yields results in C/kg. 1 C/kg ≈ 3876 R.
About Roentgens
The roentgen (R) equals exactly 2.58 × 10⁻⁴ C/kg, the historical unit of X-ray and gamma-ray exposure defined in 1928 (ICRU) and redefined exactly in 1962. Still widely used in the US: field survey instruments read in R/h; NRC and EPA regulations cite R and mR; the Chernobyl accounts famously reported readings in R/h. 1 R = 2.58 × 10⁻⁴ C/kg.
Quick Reference Table
| Coulombs per kilogram (C/kg) | Roentgens (R) |
|---|---|
| 1 C/kg | 3875.97 R |
| 2 C/kg | 7751.94 R |
| 5 C/kg | 19379.8 R |
| 10 C/kg | 38759.7 R |
| 25 C/kg | 96899.2 R |
| 50 C/kg | 193798 R |
| 100 C/kg | 387597 R |