How to convert roentgens to milliroentgens
mR = R × 1,000Multiply the value in roentgens by 1,000. To go the other way, multiply by 0.001 (or divide by 1,000).
A roentgen is larger than a milliroentgen: one roentgen contains 1,000 milliroentgens.
Worked examples
- 1 roentgen1 R × 1,000 = 1,000 mR
- 5 roentgens5 R × 1,000 = 5,000 mR
- 10 roentgens10 R × 1,000 = 10,000 mR
- 20 roentgens20 R × 1,000 = 20,000 mR
- 100 roentgens100 R × 1,000 = 100,000 mR
Roentgens to milliroentgens conversion table
Values are calculated by the conversion engine and rounded to 8 significant figures.
| Roentgens (R) | Milliroentgens (mR) |
|---|---|
| 0.1 R | 100 mR |
| 0.25 R | 250 mR |
| 0.5 R | 500 mR |
| 1 R | 1,000 mR |
| 2 R | 2,000 mR |
| 3 R | 3,000 mR |
| 4 R | 4,000 mR |
| 5 R | 5,000 mR |
| 6 R | 6,000 mR |
| 7 R | 7,000 mR |
| 8 R | 8,000 mR |
| 9 R | 9,000 mR |
| 10 R | 10,000 mR |
| Roentgens (R) | Milliroentgens (mR) |
|---|---|
| 12 R | 12,000 mR |
| 15 R | 15,000 mR |
| 20 R | 20,000 mR |
| 25 R | 25,000 mR |
| 30 R | 30,000 mR |
| 40 R | 40,000 mR |
| 50 R | 50,000 mR |
| 75 R | 75,000 mR |
| 100 R | 100,000 mR |
| 250 R | 250,000 mR |
| 500 R | 500,000 mR |
| 1,000 R | 1,000,000 mR |
About the units
Roentgen (R)
The roentgen (R) is a unit of radiation exposure. One roentgen equals 0.000258 coulombs per kilogram (C/kg).
Milliroentgen (mR)
The milliroentgen (mR) is a unit of radiation exposure. One milliroentgen equals 2.58×10⁻⁷ coulombs per kilogram (C/kg).
Frequently asked questions
How many milliroentgens are in one roentgen?
There are 1,000 milliroentgens in one roentgen, and this value is exact by definition.
How do I convert roentgens to milliroentgens?
Multiply the number of roentgens by 1,000. For example, 10 R × 1,000 = 10,000 mR.
How many roentgens are in one milliroentgen?
One milliroentgen equals 0.001 roentgens. That is the reverse factor, 1 ÷ 1,000.
What is 10 roentgens in milliroentgens?
10 R = 10,000 mR.
Is this R to mR converter accurate?
Yes. Both units are defined exactly in terms of SI units, so the conversion factor is exact; results are shown to 12 significant figures by default and you can change precision in the converter. Calculations run in your browser using the same tested engine that generated this page.