Radiation Exposure Converter
Convert radiation exposure: C/kg, roentgen.
6 decimals
1 C/kg = 3875.968992 R
About the radiation exposure converter
Radiation exposure measures the ionization that X-rays or gamma rays produce in air, in coulombs of charge per kilogram of air. The SI unit is the coulomb per kilogram (C/kg); the historical unit, still used in radiation safety, is the roentgen (R), where 1 R = 2.58 × 10⁻⁴ C/kg. Exposure relates to absorbed dose but is specifically defined for air and photons rather than tissue.
Frequently asked questions
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How is exposure different from absorbed dose?
Exposure (C/kg or R) measures ionization in air; absorbed dose (Gy) measures energy deposited per kg in any material. For X-rays in soft tissue, 1 R ≈ 0.0096 Gy.
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Is the roentgen still used?
It is being phased out in favor of SI units, but you still see it on older survey meters and in regulatory documents.
More radiology converters
Complete list of radiation exposure units
- Coulomb/kilogram [C/kg]