Convert Centigrays to Grays (cGy to Gy)
1 centigray (cGy) = 0.01 grays (Gy). 1 Gy = 100 cGy. Example: 15 cGy = 15 × 0.01 = 0.15 Gy.
Also searched as centigrays to Gy, centigrays in Gy, centigrays into grays, cGy to Gy, cGy in grays, cGy into gray, centigray to gray, cGy to grays converter and how many grays in a centigray.
1 cGy = 0.01 Gy
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk centigray to gray converter to paste a column from Excel.
How to Convert Centigray to Gray
- 1 cGy = 0.01 Gy
- 1 Gy = 100 cGy
- Example: convert 15 cGy to Gy: 15 cGy = 15 × 0.01 Gy = 0.15 Gy
Formula
Gy = cGy ÷ 100
Derivation from SI units:
- 1 cGy = 0.01 Gy = 1 rad.
- 1 Gy = 1 J of absorbed energy per kg.
Both units are defined exactly, so the factor is exact. Centigray definition: centigray; Gray definition: gray.
Worked examples
- A reading of 100 cGy converts to 1 Gy.
100 cGy × 0.01 = 1 Gy - A value of 500 cGy is 5 Gy.
500 cGy × 0.01 = 5 Gy
Centigray to Gray conversion table
| Centigrays (cGy) | Grays (Gy) |
|---|---|
| 1 cGy | 0.01 Gy |
| 10 cGy | 0.1 Gy |
| 50 cGy | 0.5 Gy |
| 100 cGy | 1 Gy |
| 180 cGy | 1.8 Gy |
| 200 cGy | 2 Gy |
| 500 cGy | 5 Gy |
| 1000 cGy | 10 Gy |
| 5000 cGy | 50 Gy |
| 7000 cGy | 70 Gy |
Where it's used
Centigrays are used for radiotherapy plans (e.g. 200 cGy per fraction), while grays appear in radiotherapy prescriptions. Both measure absorbed dose of ionising radiation, so the conversion is a fixed factor.
Centigray to other absorbed dose units
| Conversion | 1 cGy equals |
|---|---|
| centigray to gray | 0.01 Gy |
| centigray to milligray | 10 mGy |
| centigray to rad | 1 rad |
| centigray to microgray | 10000 µGy |
| centigray to kilogray | 0.00001 kGy |
| centigray to millirad | 1000 mrad |
Frequently asked questions
How many grays are in 1 centigray?
1 cGy = 0.01 Gy.
How do I convert centigrays to grays?
Multiply the value in cGy by 0.01, or divide it by 100. For example, 15 cGy × 0.01 = 0.15 Gy.
Is the cGy to Gy conversion exact?
Yes. Both units are defined exactly, and 1 cGy is exactly 0.01 Gy.
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). Convert Centigrays to Grays (cGy to Gy). Retrieved October 25, 2026, from https://scientificconverters.com/absorbed-dose/centigrays-to-grays/
IEEE
Scientific Converters, "Convert Centigrays to Grays (cGy to Gy)," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/absorbed-dose/centigrays-to-grays/