Convert Roentgens to Milliroentgens
Convert Roentgens (R) to Milliroentgens (mR) instantly and accurately.
Conversion Formula
mR = R × 1000
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 Milliroentgens
The milliroentgen (mR) equals 2.58 × 10⁻⁷ C/kg. Standard unit in US health physics for area gamma surveys: personal dosimeters and Geiger counters in medical and industrial radiography settings display mR/h; NRC licence conditions often specify dose-rate limits in mR/h at facility boundaries. 1 mR = 2.58 × 10⁻⁷ C/kg.
Quick Reference Table
| Roentgens (R) | Milliroentgens (mR) |
|---|---|
| 1 R | 1000 mR |
| 2 R | 2000 mR |
| 5 R | 5000 mR |
| 10 R | 10000 mR |
| 25 R | 25000 mR |
| 50 R | 50000 mR |
| 100 R | 100000 mR |