Convert Grays to Millirads (Gy to mrad)
1 gray (Gy) = 100000 millirads (mrad). 1 mrad = 0.00001 Gy. Example: 15 Gy = 15 × 100000 = 1500000 mrad.
Also searched as grays to mrad, grays in mrad, grays into millirads, Gy to mrad, Gy in millirads, Gy into millirad, gray to millirad, Gy to millirads converter and how many millirads in a gray.
1 Gy = 100000 mrad
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk gray to millirad converter to paste a column from Excel.
How to Convert Gray to Millirad
- 1 Gy = 100000 mrad
- 1 mrad = 0.00001 Gy
- Example: convert 15 Gy to mrad: 15 Gy = 15 × 100000 mrad = 1500000 mrad
Formula
mrad = Gy × 100000
Derivation from SI units:
- 1 Gy = 1 J of absorbed energy per kg.
- 1 mrad = 10⁻⁵ Gy = 10 µGy.
Both units are defined exactly, so the factor is exact. Gray definition: gray; Millirad definition: millirad.
Worked examples
- A reading of 0.5 Gy converts to 50000 mrad.
0.5 Gy × 100000 = 50000 mrad - A value of 5 Gy is 500000 mrad.
5 Gy × 100000 = 500000 mrad
Gray to Millirad conversion table
| Grays (Gy) | Millirads (mrad) |
|---|---|
| 0.001 Gy | 100 mrad |
| 0.01 Gy | 1000 mrad |
| 0.1 Gy | 10000 mrad |
| 0.5 Gy | 50000 mrad |
| 1 Gy | 100000 mrad |
| 2 Gy | 200000 mrad |
| 5 Gy | 500000 mrad |
| 10 Gy | 1000000 mrad |
| 50 Gy | 5000000 mrad |
| 100 Gy | 10000000 mrad |
Where it's used
Grays are used for radiotherapy prescriptions, while millirads appear in older X-ray dose figures. Both measure absorbed dose of ionising radiation, so the conversion is a fixed factor.
Gray to other absorbed dose units
| Conversion | 1 Gy equals |
|---|---|
| gray to millirad | 100000 mrad |
| gray to milligray | 1000 mGy |
| gray to rad | 100 rad |
| gray to microgray | 1000000 µGy |
| gray to centigray | 100 cGy |
| gray to kilogray | 0.001 kGy |
Frequently asked questions
How many millirads are in 1 gray?
1 Gy = 100000 mrad.
How do I convert grays to millirads?
Multiply the value in Gy by 100000. For example, 15 Gy × 100000 = 1500000 mrad.
Is the Gy to mrad conversion exact?
Yes. Both units are defined exactly, and 1 Gy is exactly 100000 mrad.
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 4 (becquerel, gray, sievert, lux) and Table 2 (candela).
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "rad (absorbed dose)".
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Grays to Millirads (Gy to mrad). Retrieved October 25, 2026, from https://scientificconverters.com/absorbed-dose/grays-to-millirads/
IEEE
Scientific Converters, "Convert Grays to Millirads (Gy to mrad)," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/absorbed-dose/grays-to-millirads/