Radiation Exposure Unit Converter
Convert ionizing-radiation exposure between C/kg, roentgen and their prefixes.
YOUR CALCULATION
Result
—
Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Normalize the defined ionization charge per mass of air to C/kg.
1 roentgen = 2.58×10⁻⁴ C/kg
Worked example
1 R is 258 µC/kg. One mR is 0.258 µC/kg.
Assumptions and input details
Exposure here is the defined X-ray or gamma-ray ionization quantity in air, not general time near a source, absorbed dose in tissue or equivalent dose. There is no universal R-to-Gy or R-to-Sv unit conversion without additional physical information. No radiation energy, tissue properties, instrument calibration or exposure limit is assumed.
References: NIST: conversion factors by quantity · BIPM: SI quantities and prefixes
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
Convert the same absorbed dose between gray, rad and their prefixes.
Convert a known equivalent or effective dose between sievert, rem and their prefixes.
Enter a list of numbers to calculate mean, median, modes, quartiles, population and sample standard deviation, with a frequency histogram.
Reserved advertising space.