| Isotope | Mass in Atomic Unit (u) | |
| Experimental | Theoretical | |
| 1H | 1.007276466812 (90) | 1.0072764660 |
| 4He | 4.0015059 | 4.0015059 (5) |
| 6Li | 6.0134768 | 6.0134767 |
| 9Be | 9.0100138 | 9.0100225 |
| 10B | 10.010194 | 10.010188 |
| 12C | 11.996708 | 11.996708 |
| 16O | 15.990525 | 15.990526 |
| 25Mg | 24.979252 | 24.979246 |
| 27Al | 26.974405 | 26.974407 |
| 28Si | 27.969245 | 27.969245 |