Convert Roentgens to Megaroentgens
Convert Roentgens (R) to Megaroentgens (MR) instantly and accurately.
Conversion Formula
MR = R × 1.000000000e-6
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.
About Megaroentgens
The megaroentgen (MR) equals 258 C/kg. Used only in extreme radiation environments - nuclear detonation effects calculations, prompt gamma pulse environments, and legacy radiation hardness assurance for military electronics specify total ionising exposure in MR(air); calibrated flash X-ray simulators output pulse exposures in MR. 1 MR = 258 C/kg = 10⁶ R.
Quick Reference Table
| Roentgens (R) | Megaroentgens (MR) |
|---|---|
| 1 R | 1 × 10-6 MR |
| 2 R | 2 × 10-6 MR |
| 5 R | 5 × 10-6 MR |
| 10 R | 1 × 10-5 MR |
| 25 R | 2.5 × 10-5 MR |
| 50 R | 5 × 10-5 MR |
| 100 R | 1 × 10-4 MR |