Radiation Absorbed Dose Converter — Gray (Gy), Rad
Convert between 5 units of radiation absorbed dose — gray (Gy), milligray (mGy), centigray (cGy), rad, and millirad. 1 Gy = 1 J/kg absorbed energy = 100 rad. A chest X-ray delivers ~0.1 mGy; a CT scan delivers 10–30 mGy; cancer radiation therapy delivers 60–80 Gy to the tumour over several weeks. Acute radiation sickness begins above ~1 Gy whole-body dose.
About the Radiation Absorbed Dose Converter
Absorbed dose measures the energy deposited by ionising radiation per unit mass of tissue or material. The SI unit is the gray (Gy), where 1 Gy = 1 joule per kilogram. The older unit, the rad, is still used in US medical contexts (1 Gy = 100 rad). Absorbed dose tells us the raw energy delivered but not the biological effect — for that, effective dose in sieverts accounts for radiation type and tissue sensitivity.
- ›A chest X-ray delivers about 0.1 mGy (0.01 rad) of absorbed dose
- ›A CT scan delivers 10–30 mGy depending on the body region scanned
- ›Radiation therapy for cancer can deliver 60–80 Gy to a tumour over 6–8 weeks
- ›Acute radiation sickness begins at whole-body doses above ~1 Gy received in a short time