Radiology: absorbed dose converter
Absorbed dose (gray) and equivalent dose (sievert) are different quantities and cannot be converted into each other without a radiation weighting factor.
1 rad (dose) = 0.01 gray
How it’s calculated
Gy = rad × 0.01
- Multiply the value in rad by 0.01.
- To go back, divide by 0.01 (or multiply by 100).
- 1 rad = 0.01 Gy · 1 Gy = 100 rad
Show worked solutionFactor, unit cancellation and rounding, step by step
Find the conversion factor
By definition 1 Gy = 100 rad. Source: NIST SP 811 / Handbook 44; BIPM SI Brochure (9th ed.).
Multiply by the factor written as a fraction
Put rad in the denominator so it cancels, leaving Gy.
Calculate (unrounded)
Round the answer
Rounded to 5 significant figures.
Answer: 0.01 Gy
1 rad in other units
Batch convert rad → Gy
- 1 rad = 0.01 Gy
- 5 rad = 0.05 Gy
- 10 rad = 0.1 Gy
- 25 rad = 0.25 Gy
Common radiology: absorbed dose conversions
Radiology: absorbed dose units and exact definitions
| Unit | System | Definition |
|---|---|---|
| Gray (Gy) | SI (metric) | Base unit |
| Milligray (mGy) | SI (metric) | 1 mGy = 0.001 Gy |
| Centigray (cGy) | SI (metric) | 1 cGy = 0.01 Gy |
| Rad (dose) (rad) | other | 1 rad = 0.01 Gy |
Rad to gray conversion table
| Rad (rad) | Gray (Gy) |
|---|---|
| 0.1 rad | 0.001 Gy |
| 0.5 rad | 0.005 Gy |
| 1 rad | 0.01 Gy |
| 2 rad | 0.02 Gy |
| 3 rad | 0.03 Gy |
| 4 rad | 0.04 Gy |
| 5 rad | 0.05 Gy |
| 6 rad | 0.06 Gy |
| 7 rad | 0.07 Gy |
| 8 rad | 0.08 Gy |
| 9 rad | 0.09 Gy |
| 10 rad | 0.1 Gy |
| 15 rad | 0.15 Gy |
| 20 rad | 0.2 Gy |
| 25 rad | 0.25 Gy |
| 30 rad | 0.3 Gy |
| 40 rad | 0.4 Gy |
| 50 rad | 0.5 Gy |
| 75 rad | 0.75 Gy |
| 100 rad | 1 Gy |
| 250 rad | 2.5 Gy |
| 500 rad | 5 Gy |
| 1,000 rad | 10 Gy |
Frequently asked questions
Which radiology: absorbed dose units can I convert?
gray (Gy), milligray (mGy), centigray (cGy), rad (rad).
How accurate are the results?
Every unit is stored with its exact defining factor (NIST SP 811, NIST Handbook 44 or the BIPM SI Brochure). Calculations use double-precision arithmetic and are rounded only for display, to 5 significant figures by default (trailing zeros dropped, so 1 km shows as 1000 m). You can choose Auto (up to 10 digits), fixed decimals or more significant figures, or switch to scientific or engineering notation.