| Age | Approx. start | Approx. duration | Notes |
| First | c 11,850 BCE | c 600 yrs. | Men awaken; Siege of Angband; Wars of Beleriand. Ends with defeat of Morgoth. |
| Second | 11,242 BCE | 3,441 yrs.* | Rise and fall of Númenor; assault on Blessed Realm; Drowning of Númenor and changing of World. Ends with overthrow of Sauron by Last Alliance. |
| Third | 7,801 BCE | 3,021 yrs.* | Rise of Arnor & Gondor; return of Sauron & Nazgûl. Ends with the WotR. |
| Fourth | 4,780 BCE | 2,600 yrs. | The 'Age of Men'; Most Elves pass into the West. |
| Fifth | 2,180 BCE | 2,180 yrs. | |
| Sixth | 1 CE | 2,000 yrs. | The present Age (AD, or Common Era). |
| Seventh | 2,000 CE | (unknown) | The 'New Age' |