Centigray (cGy)
A centigray is one hundredth of a gray, numerically equal to the old rad, which is why radiotherapy plans often use cGy.
Symbol: cGy
Quantity: absorbed dose of ionising radiation
SI relation: 1 cGy = 0.01 Gy (exact)
Derivation: 1 cGy = 0.01 Gy = 1 rad.
Exact: yes, by definition
Same quantity as rad (rad) : the factor between them is exactly 1.
Typical uses
- Radiotherapy plans (e.g. 200 cGy per fraction)
Convert centigrays to other units
| Conversion | 1 cGy equals | Reverse |
|---|---|---|
| centigray to gray | 0.01 Gy | gray to centigray |
| centigray to milligray | 10 mGy | milligray to centigray |
| centigray to rad | 1 rad | rad to centigray |
| centigray to microgray | 10000 µGy | microgray to centigray |
| centigray to kilogray | 0.00001 kGy | kilogray to centigray |
| centigray to millirad | 1000 mrad | millirad to centigray |
Open the Absorbed Radiation Dose Converter to convert any value between all units.
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 4 (becquerel, gray, sievert, lux) and Table 2 (candela).
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Centigray (cGy). Retrieved October 25, 2026, from https://scientificconverters.com/units/centigray/
IEEE
Scientific Converters, "Centigray (cGy)," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/units/centigray/