1 roentgen (R) equals 0.258 millicoulomb/kilogram (mC/kg). Enter any value below to convert from R to mC/kg.
Enter a value and choose units. Results update instantly.
1 R = 0.258 mC/kg
All Radiation - Exposure units
From 1 R
Unit
Value
Coulomb/kilogram C/kg
0.000258
Millicoulomb/kilogram mC/kg
0.258
Microcoulomb/kilogram µC/kg
258
Roentgen R
1
Milliroentgen mR
1,000
Microroentgen µR
1,000,000
Parker parker
1
Rep rep
1
Sievert Sv
0.000258
Millisievert mSv
0.258
Microsievert µSv
258
Rem rem
0.0258
Millirem mrem
25.8
Recent conversions
Your recent conversions stay on this device.
Formula
R to mC/kg conversion formula
Use this relationship for a direct conversion:
mC/kg = R x 0.258
Worked example
2 R = 0.516 mC/kg.
SI relationships follow the cited reference. Conventional and domain-specific factors use the established ConvertWin factor inventory; verify safety-critical work against the governing standard.
Quick reference
Roentgen to Millicoulomb/kilogram table
Roentgen (R)
Millicoulomb/kilogram (mC/kg)
0.01
0.00258
0.1
0.0258
1
0.258
2
0.516
5
1.29
10
2.58
25
6.45
50
12.9
100
25.8
1,000
258
From unit
About the roentgen
Roentgen (R) is a unit of Radiation - Exposure. 1 R = 0.000258 C/kg
Symbol: R
To unit
About the millicoulomb/kilogram
Millicoulomb/kilogram (mC/kg) is a metric prefix submultiple of the Coulomb/kilogram (C/kg). 1 C/kg = 1,000 mC/kg.
How do you convert roentgen to millicoulomb/kilogram?
Use the formula mC/kg = R x 0.258. 1 roentgen (R) equals 0.258 millicoulomb/kilogram (mC/kg).
Is the R to mC/kg conversion exact?
SI relationships follow the cited reference. Conventional and domain-specific factors use the established ConvertWin factor inventory; verify safety-critical work against the governing standard.