Convert Grays to Kilograys (Gy to kGy)
1 gray (Gy) = 0.001 kilograys (kGy). 1 kGy = 1000 Gy. Example: 15 Gy = 15 × 0.001 = 0.015 kGy.
Also searched as grays to kGy, grays in kGy, grays into kilograys, Gy to kGy, Gy in kilograys, Gy into kilogray, gray to kilogray, Gy to kilograys converter and how many kilograys in a gray.
1 Gy = 0.001 kGy
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk gray to kilogray converter to paste a column from Excel.
How to Convert Gray to Kilogray
- 1 Gy = 0.001 kGy
- 1 kGy = 1000 Gy
- Example: convert 15 Gy to kGy: 15 Gy = 15 × 0.001 kGy = 0.015 kGy
Formula
kGy = Gy ÷ 1000
Derivation from SI units:
- 1 Gy = 1 J of absorbed energy per kg.
- 1 kGy = 10³ Gy.
Both units are defined exactly, so the factor is exact. Gray definition: gray; Kilogray definition: kilogray.
Worked examples
- A reading of 0.5 Gy converts to 0.0005 kGy.
0.5 Gy × 0.001 = 0.0005 kGy - A value of 5 Gy is 0.005 kGy.
5 Gy × 0.001 = 0.005 kGy
Gray to Kilogray conversion table
| Grays (Gy) | Kilograys (kGy) |
|---|---|
| 0.001 Gy | 0.000001 kGy |
| 0.01 Gy | 0.00001 kGy |
| 0.1 Gy | 0.0001 kGy |
| 0.5 Gy | 0.0005 kGy |
| 1 Gy | 0.001 kGy |
| 2 Gy | 0.002 kGy |
| 5 Gy | 0.005 kGy |
| 10 Gy | 0.01 kGy |
| 50 Gy | 0.05 kGy |
| 100 Gy | 0.1 kGy |
Where it's used
Grays are used for radiotherapy prescriptions, while kilograys appear in sterilisation of medical devices (25 kGy). 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 kilogray | 0.001 kGy |
| gray to milligray | 1000 mGy |
| gray to rad | 100 rad |
| gray to microgray | 1000000 µGy |
| gray to centigray | 100 cGy |
| gray to millirad | 100000 mrad |
Frequently asked questions
How many kilograys are in 1 gray?
1 Gy = 0.001 kGy.
How do I convert grays to kilograys?
Multiply the value in Gy by 0.001, or divide it by 1000. For example, 15 Gy × 0.001 = 0.015 kGy.
Is the Gy to kGy conversion exact?
Yes. Both units are defined exactly, and 1 Gy is exactly 0.001 kGy.
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).
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 Kilograys (Gy to kGy). Retrieved October 25, 2026, from https://scientificconverters.com/absorbed-dose/grays-to-kilograys/
IEEE
Scientific Converters, "Convert Grays to Kilograys (Gy to kGy)," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/absorbed-dose/grays-to-kilograys/