Convert Millicoulombs per kilogram to Roentgens
Convert Millicoulombs per kilogram (mC/kg) to Roentgens (R) instantly and accurately.
Conversion Formula
R = mC/kg × 3.875968992
About Millicoulombs per kilogram
The millicoulomb per kilogram (mC/kg) equals 10⁻³ C/kg ≈ 3.88 R. Used in high-dose-rate X-ray beam calibration protocols (IAEA TRS-398, AAPM TG-51) where free-air chambers accumulate mC/kg of charge per irradiation; high-energy medical linac beams deliver calibration exposures measured in mC/kg. 1 mC/kg = 10⁻³ C/kg ≈ 3.88 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
| Millicoulombs per kilogram (mC/kg) | Roentgens (R) |
|---|---|
| 1 mC/kg | 3.87597 R |
| 2 mC/kg | 7.75194 R |
| 5 mC/kg | 19.3798 R |
| 10 mC/kg | 38.7597 R |
| 25 mC/kg | 96.8992 R |
| 50 mC/kg | 193.798 R |
| 100 mC/kg | 387.597 R |