Radiation Dose Converter
Radiation dose describes how much ionising-radiation energy a body absorbs. The gray is the SI unit of absorbed dose (one joule per kilogram); the sievert is the same size but weights the dose for biological effect. For X-rays, gamma and beta radiation the weighting factor is 1, so grays and sieverts convert one-for-one; for alpha particles and neutrons they do not. The older rad and rem are each one hundredth of their SI counterparts.
29 units supported Base unit gray (Gy)
About radiation dose conversion
Radiation Dose conversion is commonly needed when medical imaging, occupational safety, and radiotherapy planning. Grays measure absorbed energy while sieverts weight it for biological harm; they match one-for-one only for X-rays, gamma, and beta radiation.
Popular conversions
Convert Sievert to other radiation dose units
1 Sv expressed in every other radiation dose unit on this site.
- Gray Gy 1
- Kilogray kGy 0.001
- Milligray mGy 1,000
- Microgray µGy 1,000,000
- Rad rad 100
- Millirad mrad 100,000
- Joule per Kilogram J/kg 1
- Joule per Centigram J/cg 0.00001
- Joule per Milligram J/mg 0.000001
- Megagray MGy 0.000001
- Dekagray daGy 0.1
- Decigray dGy 10
- Exagray EGy 1e-18
- Petagray PGy 1e-15
- Teragray TGy 1e-12
- Gigagray GGy 1e-9
- Hectogray hGy 0.01
- Nanogray nGy 1,000,000,000
- Picogray pGy 1,000,000,000,000
- Femtogray fGy 1,000,000,000,000,000
- Attogray aGy 1e+18
- Joule per Gram J/g 0.001
- Erg per Gram erg/g 10,000
- Sievert Sv 1
- Millisievert mSv 1,000
- Microsievert µSv 1,000,000
- Nanosievert nSv 1,000,000,000
- Rem rem 100
- Millirem mrem 100,000
Complete list of radiation dose units
All 29 units this converter supports, each stated against the gray (Gy).
| Unit | Symbol | System | In grays | Conversions |
|---|---|---|---|---|
| Gray | Gy | SI | base unit (Gy) | gray to rad |
| Kilogray | kGy | SI | 1 kGy = 1,000 Gy | — |
| Milligray | mGy | SI | 1 mGy = 0.001 Gy | — |
| Microgray | µGy | SI | 1 µGy = 0.000001 Gy | — |
| Rad | rad | Other | 1 rad = 0.01 Gy | rad to gray |
| Millirad | mrad | Other | 1 mrad = 0.00001 Gy | — |
| Joule per Kilogram | J/kg | SI | 1 J/kg = 1 Gy | — |
| Joule per Centigram | J/cg | SI | 1 J/cg = 100,000 Gy | — |
| Joule per Milligram | J/mg | SI | 1 J/mg = 1,000,000 Gy | — |
| Megagray | MGy | SI | 1 MGy = 1,000,000 Gy | — |
| Dekagray | daGy | SI | 1 daGy = 10 Gy | — |
| Decigray | dGy | SI | 1 dGy = 0.1 Gy | — |
| Exagray | EGy | SI | 1 EGy = 1e+18 Gy | — |
| Petagray | PGy | SI | 1 PGy = 1e+15 Gy | — |
| Teragray | TGy | SI | 1 TGy = 1,000,000,000,000 Gy | — |
| Gigagray | GGy | SI | 1 GGy = 1,000,000,000 Gy | — |
| Hectogray | hGy | SI | 1 hGy = 100 Gy | — |
| Nanogray | nGy | SI | 1 nGy = 1e-9 Gy | — |
| Picogray | pGy | SI | 1 pGy = 1e-12 Gy | — |
| Femtogray | fGy | SI | 1 fGy = 1e-15 Gy | — |
| Attogray | aGy | SI | 1 aGy = 1e-18 Gy | — |
| Joule per Gram | J/g | SI | 1 J/g = 1,000 Gy | — |
| Erg per Gram | erg/g | Metric | 1 erg/g = 0.0001 Gy | — |
| Sievert | Sv | SI | 1 Sv = 1 Gy | sievert to rem |
| Millisievert | mSv | SI | 1 mSv = 0.001 Gy | msv to mrem |
| Microsievert | µSv | SI | 1 µSv = 0.000001 Gy | — |
| Nanosievert | nSv | SI | 1 nSv = 1e-9 Gy | — |
| Rem | rem | Other | 1 rem = 0.01 Gy | rem to sievert |
| Millirem | mrem | Other | 1 mrem = 0.00001 Gy | mrem to msv |
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Frequently asked questions
What is the base unit for radiation dose?
Radiation Dose conversions on this site are calculated against the gray (Gy).
Which radiation dose units can I convert?
You can convert between 29 units, including gray, kilogray, milligray, microgray, and more.
Where is radiation dose conversion useful?
It is commonly needed when medical imaging, occupational safety, and radiotherapy planning.
Does this converter mix measurement systems?
The converter supports SI, Other, Metric units and keeps their exact definitions separate so results stay accurate.
Related categories
Conversion factors are based on internationally agreed unit definitions. See our methodology and sources for details on how these values are verified.