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.
Gray to Centigray
Convert gray to centigray instantly. Type in either field — results update live.
Instant
Private
Free
radiation-absorbed-dose Gray Centigray
1 gray = 100 centigrays
Unit
Unit
Conversion table
Selected Gy values converted to cGy using the exact factor from this tool.
| Gy | cGy |
|---|---|
| 0.01 | 1 |
| 0.1 | 10 |
| 1 | 100 |
| 2 | 200 |
| 3 | 300 |
| 5 | 500 |
| 10 | 1,000 |
| 20 | 2,000 |
| 50 | 5,000 |
| 100 | 10,000 |
| 1,000 | 100,000 |
How to convert
Exact conversion factors in both directions, plus a worked example.
1 Gy = 100 cGy
1 cGy = 0.01 Gy
To convert gray to centigray, multiply by 100.
To convert centigray to gray, multiply by 0.01.
Example: convert 10 Gy to cGy
10 × 100 = 1000 cGy
About these units
Short background on the units used in this conversion.
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.
Frequently asked questions
How many centigrays are in one gray?
One gray equals 100 centigrays. Multiply your grays value by 100 to convert to centigrays.
What is the conversion formula?
cGy = Gy × 100The reverse is
Gy = cGy × 0.01, using the same exact factors as this converter.Is this Gray to Centigray converter private?
Yes. All calculations run locally in your browser. Nothing you type is sent to a server.