Convert Rads to Centigrays (rad to cGy)
1 rad = 1 centigray (cGy). 1 cGy = 1 rad. Example: 15 rad = 15 × 1 = 15 cGy.
Also searched as rads to cGy, rads in cGy, rads into centigrays, rad to cGy, rad in centigrays, rad into centigray, rad to centigray, rad to centigrays converter and how many centigrays in a rad.
1 rad = 1 cGy
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk rad to centigray converter to paste a column from Excel.
How to Convert Rad to Centigray
- 1 rad = 1 cGy
- 1 cGy = 1 rad
- Example: convert 15 rad to cGy: 15 rad = 15 × 1 cGy = 15 cGy
Formula
cGy = rad × 1
Derivation from SI units:
- 1 rad = 100 erg/g = 0.01 Gy.
- 1 cGy = 0.01 Gy = 1 rad.
- 1 rad = 0.01 Gy ÷ 0.01 Gy per cGy = 1 cGy
Both units are defined exactly, so the factor is exact. Rad definition: rad; Centigray definition: centigray.
Worked examples
- A reading of 0.5 rad converts to 0.5 cGy.
0.5 rad × 1 = 0.5 cGy - A value of 5 rad is 5 cGy.
5 rad × 1 = 5 cGy
Rad to Centigray conversion table
| Rads (rad) | Centigrays (cGy) |
|---|---|
| 0.001 rad | 0.001 cGy |
| 0.01 rad | 0.01 cGy |
| 0.1 rad | 0.1 cGy |
| 0.5 rad | 0.5 cGy |
| 1 rad | 1 cGy |
| 2 rad | 2 cGy |
| 5 rad | 5 cGy |
| 10 rad | 10 cGy |
| 50 rad | 50 cGy |
| 100 rad | 100 cGy |
Where it's used
Rads are used for US radiation safety and older literature, while centigrays appear in radiotherapy plans (e.g. 200 cGy per fraction). Both measure absorbed dose of ionising radiation, so the conversion is a fixed factor.
Rad to other absorbed dose units
| Conversion | 1 rad equals |
|---|---|
| rad to centigray | 1 cGy |
| rad to gray | 0.01 Gy |
| rad to milligray | 10 mGy |
| rad to microgray | 10000 µGy |
| rad to kilogray | 0.00001 kGy |
| rad to millirad | 1000 mrad |
Frequently asked questions
How many centigrays are in 1 rad?
1 rad = 1 cGy.
How do I convert rads to centigrays?
Multiply the value in rad by 1. For example, 15 rad × 1 = 15 cGy.
Is the rad to cGy conversion exact?
Yes. Both units are defined exactly, and 1 rad is exactly 1 cGy.
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)".
- 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). Convert Rads to Centigrays (rad to cGy). Retrieved October 25, 2026, from https://scientificconverters.com/absorbed-dose/rads-to-centigrays/
IEEE
Scientific Converters, "Convert Rads to Centigrays (rad to cGy)," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/absorbed-dose/rads-to-centigrays/