Radiation-Exposure Converter
Convert radiation exposure between coulombs per kilogram and roentgens.
Written by Rahman · Last reviewed
Quick answer
Exposure measures the ionisation that radiation produces in air. The SI unit is the coulomb per kilogram, and one roentgen is 2.58 × 10⁻⁴ C/kg. The roentgen is a legacy unit defined only for X-rays and gamma rays in air, which is why absorbed dose in grays is preferred for anything involving tissue.
| Coulomb per kilogram (C/kg) | 1 |
| Millicoulomb per kilogram (mC/kg) | 1000 |
| Microcoulomb per kilogram (µC/kg) | 1000000 |
| Roentgen (R) | 3875.968992 |
About the Radiation-Exposure Converter
Radiation exposure measures how strongly X-rays or gamma rays ionise air. The SI unit is the coulomb per kilogram; the roentgen is the traditional unit.
It is used in radiology and radiation monitoring.
Frequently Asked Questions
What is radiation exposure?
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Exposure measures the amount of ionisation that X-rays or gamma rays produce in air.
What is a roentgen?
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The roentgen is the traditional unit of radiation exposure, equal to about 0.000258 coulombs per kilogram.
How is exposure different from absorbed dose?
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Exposure measures ionisation in air; absorbed dose measures the energy actually deposited in a material or tissue.