Convert Rad to Gray
Use this free converter to change rad (rad) into gray (Gy). Rad and gray both measure radiation (absorbed dose). As a quick reference, 1 rad equals 0.01 Gy, and 1 Gy equals 100 rad.
Free · runs in your browser · no sign-up
Gray (Gy)
0.01
1 rad = 0.01 Gy
Radiation (Absorbed Dose) conversion table
| Rad | Gray |
|---|---|
| 0.01 | 0.0001 |
| 0.1 | 0.001 |
| 0.5 | 0.005 |
| 1 | 0.01 |
| 2 | 0.02 |
| 3 | 0.03 |
| 5 | 0.05 |
| 10 | 0.1 |
| 20 | 0.2 |
| 25 | 0.25 |
| 50 | 0.5 |
| 100 | 1 |
| 1,000 | 10 |
How to convert Rad to Gray
Multiply the rad value by 0.01 to get gray.
- Enter the number of rad you want to convert.
- The converter instantly shows the equivalent value in gray.
- Worked example: 15 rad × 0.01 = 0.15 Gy.
- Use the swap button to reverse the conversion (gray to rad).
About these units
Rad (rad)
- Definition
- The rad (radiation absorbed dose) is a non-SI unit of absorbed dose equal to 0.01 gray or 100 ergs per gram.
- History
- Introduced in 1953 by the International Commission on Radiation Units and Measurements; largely superseded by the gray since 1985.
- Current use
- Still encountered in US medical and nuclear-industry documentation alongside cGy; 100 rad = 1 Gy.
Gray (Gy)
- Definition
- The gray (Gy) is the SI unit of absorbed radiation dose, equal to one joule of energy deposited per kilogram of matter.
- History
- Named after British radiobiologist Louis Harold Gray and adopted by the CGPM in 1975, replacing the older rad.
- Current use
- Grays describe doses in radiation therapy, nuclear accidents, and radiobiology research.
Frequently asked questions
How many gray are in a rad?
There are 0.01 Gy in 1 rad. To convert, multiply the number of rad by 0.01.
How do I convert rad to gray?
Multiply the rad value by 0.01 to get gray. For example, 10 rad = 0.1 Gy.
Is this rad-to-gray converter free?
Yes. This converter is completely free, runs entirely in your browser, and requires no sign-up. Your inputs never leave your device.
Convert Rad to other radiation (absorbed dose) units
| Unit | 1 Rad equals |
|---|---|
| Gray (Gy) | 0.01 Gy |
| Milligray (mGy) | 10 mGy |
| Centigray (cGy) | 1 cGy |
| Microgray (µGy) | 10000 µGy |