Radioactivity is the process by which an unstable atomic nucleus loses energy by radiation. It is measured in becquerels (Bq).
1 Gy = 100 rad 
1 rad = 0.01 Gy 
उदाहरण: 
कन्वर्ट 15 Gray से Rad:
15 Gy = 1,500 rad 
| Gray | Rad | 
|---|---|
| 0.01 Gy | 1 rad | 
| 0.1 Gy | 10 rad | 
| 1 Gy | 100 rad | 
| 2 Gy | 200 rad | 
| 3 Gy | 300 rad | 
| 5 Gy | 500 rad | 
| 10 Gy | 1,000 rad | 
| 20 Gy | 2,000 rad | 
| 30 Gy | 3,000 rad | 
| 40 Gy | 4,000 rad | 
| 50 Gy | 5,000 rad | 
| 60 Gy | 6,000 rad | 
| 70 Gy | 7,000 rad | 
| 80 Gy | 8,000 rad | 
| 90 Gy | 9,000 rad | 
| 100 Gy | 10,000 rad | 
| 250 Gy | 25,000 rad | 
| 500 Gy | 50,000 rad | 
| 750 Gy | 75,000 rad | 
| 1000 Gy | 100,000 rad | 
| 10000 Gy | 1,000,000 rad | 
| 100000 Gy | 10,000,000 rad |