Gray (Gy)
SI unit of absorbed dose: one joule of radiation energy absorbed per kilogram of matter.
What is a gray?
- Symbol
- Gy
- Quantity
- Absorbed Dose
- Unit system
- SI
- Definition
- SI unit of absorbed dose: one joule of radiation energy absorbed per kilogram of matter.
- Exact
- Yes, the value is exact by definition
- Source
- SI Brochure, 9th edition (BIPM, 2019)
Common applications
Used in radiotherapy, radiation biology and radiation processing to state the energy absorbed per kilogram.
Gray in other absorbed dose units
- 1 Gy = 100 cGyGray to Centigray converter
- 1 Gy = 1000 mGyMilligray
- 1 Gy = 1000000 µGyMicrogray
- 1 Gy = 100 rdGray to Rad (absorbed dose) converter
- 1 Gy = 100000 mrdMillirad
Gray quick reference
| Gray | Centigray | Rad (absorbed dose) | Milligray |
|---|---|---|---|
| 1 Gy | = 100 cGy | = 100 rd | = 1000 mGy |
| 10 Gy | = 1000 cGy | = 1000 rd | = 10000 mGy |
| 100 Gy | = 10000 cGy | = 10000 rd | = 100000 mGy |
| 1000 Gy | = 100000 cGy | = 100000 rd | = 1000000 mGy |
Where the gray fits
The next smaller absorbed dose unit is the centigray (cGy). 1 Gy = 100 cGy, and 1 cGy = 0.01 Gy.
Frequently asked questions
- How many centigrays are in one gray?
- One gray = 100 cGy (centigrays).
- How many rads are in one gray?
- One gray = 100 rd (rads).
- How many milligrays are in one gray?
- One gray = 1000 mGy (milligrays).