40s ke ngwagasome tšhupamabakeng ya Gregorian wa go thoma ka 1 Pherekgong 40 ya fela ka 31 Manthole 49. Ngwagasome 40s o wela ngwagengkgolo wa 1.
| Ngwagakete: | Ngwagakete 1 |
| Mengwagakgolo: | Ngwagakgolo 1 BC – Ngwagakgolo 1 – Ngwagakgolo 2 |
| Mengwagasome: | 10s 20s 30s – 40s – 50s 60s 70s |
| Mengwaga: | 40 41 42 43 44 45 46 47 48 49 |
| 40s-tšago tswalanya: |