Rad
The rad (radiation absorbed dose) is the older CGS unit: 100 ergs per gram, exactly 0.01 gray. It is still used in US practice.
Symbol: rad
Quantity: absorbed dose of ionising radiation
SI relation: 1 rad = 0.01 Gy (exact)
Derivation: 1 rad = 100 erg/g = 0.01 Gy.
Exact: yes, by definition
Typical uses
- US radiation safety and older literature
- Radiation hardness of electronics (krad)
Convert rads to other units
| Conversion | 1 rad equals | Reverse |
|---|---|---|
| rad to gray | 0.01 Gy | gray to rad |
| rad to milligray | 10 mGy | milligray to rad |
| rad to microgray | 10000 µGy | microgray to rad |
| rad to centigray | 1 cGy | centigray to rad |
| rad to kilogray | 0.00001 kGy | kilogray to rad |
| rad to millirad | 1000 mrad | millirad to rad |
Open the Absorbed Radiation Dose Converter to convert any value between all units.
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "rad (absorbed dose)".
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). Rad. Retrieved October 25, 2026, from https://scientificconverters.com/units/rad-absorbed-dose/
IEEE
Scientific Converters, "Rad," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/units/rad-absorbed-dose/