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 Rad
Convert gray to rad instantly. Type in either field — results update live.
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radiation-absorbed-dose Gray Rad
1 gray = 100 rads
Unit
Unit
Conversion table
Selected Gy values converted to rad using the exact factor from this tool.
| Gy | rad |
|---|---|
| 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 rad
1 rad = 0.01 Gy
To convert gray to rad, multiply by 100.
To convert rad to gray, multiply by 0.01.
Example: convert 10 Gy to rad
10 × 100 = 1000 rad
About these units
Short background on the units used in this conversion.
Rad
The rad equals 0.01 gray — the legacy CGS unit of absorbed dose, still common in US clinical radiology.
Rads label patient dose on older equipment, regulatory limits, and clinical radiography — the most searched absorbed-dose conversion with gray.
Frequently asked questions
How many rads are in one gray?
One gray equals 100 rads. Multiply your grays value by 100 to convert to rads.
What is the conversion formula?
rad = Gy × 100The reverse is
Gy = rad × 0.01, using the same exact factors as this converter.Is this Gray to Rad converter private?
Yes. All calculations run locally in your browser. Nothing you type is sent to a server.