Centigray (cGy)
The centigray (cGy) equals 0.01 gray or one rad — a convenient prefix matching typical fractionated radiotherapy doses.
cGy is widely used in radiation oncology for per-fraction and total treatment doses.
Centigray to Gray
Convert centigray to gray instantly. Type in either field — results update live.
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radiation-absorbed-dose Centigray Gray
1 centigray = 0.01 grays
Unit
Unit
Conversion table
Selected cGy values converted to Gy using the exact factor from this tool.
| cGy | Gy |
|---|---|
| 0.01 | 0.0001 |
| 0.1 | 0.001 |
| 1 | 0.01 |
| 2 | 0.02 |
| 3 | 0.03 |
| 5 | 0.05 |
| 10 | 0.1 |
| 20 | 0.2 |
| 50 | 0.5 |
| 100 | 1 |
| 1,000 | 10 |
How to convert
Exact conversion factors in both directions, plus a worked example.
1 cGy = 0.01 Gy
1 Gy = 100 cGy
To convert centigray to gray, multiply by 0.01.
To convert gray to centigray, multiply by 100.
Example: convert 10 cGy to Gy
10 × 0.01 = 0.1 Gy
About these units
Short background on the units used in this conversion.
Gray (Gy)
The gray (Gy) equals one joule per kilogram of absorbed dose — the SI unit of energy deposited by ionizing radiation per unit mass.
Grays quantify absorbed dose in radiotherapy, CT dosimetry, and radiation biology — 1 gray = 100 rad.
Frequently asked questions
How many grays are in one centigray?
One centigray equals 0.01 grays. Multiply your centigrays value by 0.01 to convert to grays.
What is the conversion formula?
Gy = cGy × 0.01The reverse is
cGy = Gy × 100, using the same exact factors as this converter.Is this Centigray to Gray converter private?
Yes. All calculations run locally in your browser. Nothing you type is sent to a server.