1 roentgen (R) equals 0.000258 coulomb/kilogram (C/kg). Enter any value below to convert from R to C/kg.
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1 R = 0.000258 C/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
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Formula
R to C/kg conversion formula
Use this relationship for a direct conversion:
C/kg = R x 0.000258
Worked example
2 R = 0.000516 C/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 Coulomb/kilogram table
Roentgen (R)
Coulomb/kilogram (C/kg)
0.01
0.00000258
0.1
0.0000258
1
0.000258
2
0.000516
5
0.00129
10
0.00258
25
0.00645
50
0.0129
100
0.0258
1,000
0.258
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 coulomb/kilogram
Coulomb/kilogram (C/kg) is the base unit of Radiation - Exposure in the International System of Units (SI).
Use the formula C/kg = R x 0.000258. 1 roentgen (R) equals 0.000258 coulomb/kilogram (C/kg).
Is the R to C/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.