Absorbed Dose Converter
Convert between grays, centigrays, milligrays, micrograys, rads and millirads.
Convert absorbed dose
Result
Absorbed Dose units
Every unit below converts to every other one in the calculator. Values are relative to the base unit, the gray (Gy).
Gray quick reference
| Gray | Centigray | Rad (absorbed dose) |
|---|---|---|
| 1 Gy | = 100 cGy | = 100 rd |
| 10 Gy | = 1000 cGy | = 1000 rd |
| 100 Gy | = 10000 cGy | = 10000 rd |
| 1000 Gy | = 100000 cGy | = 100000 rd |
Among the 6 absorbed dose units on this page, the smallest is the microgray (µGy) and the largest is the gray (Gy).
More absorbed dose conversions
About absorbed dose units
Absorbed dose is the energy that ionizing radiation deposits in matter, per unit mass. Its SI unit is the gray (Gy): one joule per kilogram. Radiotherapy is planned in grays or centigrays, and imaging doses are given in milligrays.
The older rad is exactly 0.01 Gy, so 1 Gy = 100 rad and 1 cGy = 1 rad. The gray measures energy, not biological effect; that is the sievert. Converting grays to sieverts needs a radiation weighting factor, which this converter does not apply.
Frequently asked questions
- How many rads are in a gray?
- Exactly 100. One rad is 0.01 Gy, which is the same as one centigray.
- Can I convert gray to sievert?
- Not with a single factor. A sievert is an absorbed dose in grays multiplied by a weighting factor for the radiation type. For X-rays and gamma rays the factor is 1; for alpha particles and neutrons it is higher. Use the radiation dose converter for sieverts.
- How many centigrays are in one gray?
- One gray = 100 cGy (centigrays).
- How many rads are in one gray?
- One gray = 100 rd (rads).