Milliroentgens to Roentgens Converter
Enter the radiation exposure in milliroentgens below to convert it to roentgens.
Convert Milliroentgens to Roentgens
Enter a value in milliroentgens (mR) to convert to roentgens (R).
Milliroentgen to Roentgen Conversion Table
Table showing various milliroentgen measurements converted to roentgens. Click any preset value or arrow to load it into the converter.
How to Convert Milliroentgens to Roentgens
To convert milliroentgens to roentgens, multiply the radiation exposure by the following conversion ratio: 0.001 roentgens/milliroentgen.
Since one milliroentgen is equal to 0.001 roentgens, you can use this simple formula to convert:
The radiation exposure in roentgens is equal to the radiation exposure in milliroentgens multiplied by 0.001.
For example, here's how to convert 5 milliroentgens to roentgens using the formula above.
How Many Roentgens Are in a Milliroentgen?
There are 0.001 roentgens in a milliroentgen, which is why we use this value in the formula above.
Our milliroentgen to roentgen calculator automatically converts your radiation exposure measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
Milliroentgens and roentgens are both units used to measure radiation exposure. Keep reading to learn more about each unit.
What Is a Milliroentgen?
A milliroentgen is a unit of radiation exposure equal to 0.000000258 coulombs per kilogram (C/kg), the base unit for radiation exposure. One-thousandth of a Roentgen (2.58×10⁻⁷ C/kg). [1]
The milliroentgen is classified as a standard unit of radiation exposure. Milliroentgens can be abbreviated as mR; for example, 1 milliroentgen can be written as 1 mR.
In the metric system, "milli" is the standard SI prefix for thousandths, or 10⁻³. This makes the milliroentgen (mR) a convenient decimal multiple of the coulomb per kilogram (C/kg).
In practice, milliroentgens (mR) are widely used across fine-tolerance laboratory, analytical, and micro-scale radiation exposure measurements within international standard workflows, engineering documentation, and technical data sheets.
What Is a Roentgen?
A roentgen is a unit of radiation exposure equal to 0.000258 coulombs per kilogram (C/kg), the base unit for radiation exposure. Legacy X-ray/gamma exposure unit defined as exactly 2.58×10⁻⁴ C/kg. [2]
The roentgen is classified as a standard unit of radiation exposure. Roentgens can be abbreviated as R; for example, 1 roentgen can be written as 1 R.
When working with roentgens (R) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, roentgens (R) are widely used across fine-tolerance laboratory, analytical, and micro-scale radiation exposure measurements within international standard workflows, engineering documentation, and technical data sheets.
When converting radiation exposure between milliroentgens (mR) and roentgens (R), keep full floating-point precision (1 mR = 0.001 R; 1 R = 1,000 mR) during intermediate calculations and round only the final roentgen figure to match your instrument tolerance.
More Milliroentgen & Roentgen Conversions
Need to calculate in the opposite direction? Use our roentgens to milliroentgens calculator to switch your starting unit immediately. You can also explore related tools such as converting roentgens to milliroentgens, converting coulombs per kilogram to roentgens, or converting coulombs per kilogram to millicoulombs per kilogram.
Frequently Asked Questions
References
- [1]NIST OWM StandardNIST OWM (SI Units — Length)·Radiation-Exposure Metrology Standard — Milliroentgens (mR) to Roentgens (R)
- [2]BIPM SpecificationBIPM (SI Base Unit: Metre (m))·Unit Specifications: Milliroentgen (mR) & Roentgen (R)
- [3]NIST HB 133 ReferenceNIST HB 133 (NIST Handbook 133 (2019 Ed.))·Conversion Factors & Mathematical Basis (mR to R)