| Millennium: | 1st millennium |
|---|---|
| Centuries: | |
| Decades: | |
| Years: |
| 646 by topic |
|---|
| Leaders |
| Categories |
| Gregorian calendar | 646 DCXLVI |
| Ab urbe condita | 1399 |
| Armenian calendar | 95 ԹՎ ՂԵ |
| Assyrian calendar | 5396 |
| Balinese saka calendar | 567–568 |
| Bengali calendar | 53 |
| Berber calendar | 1596 |
| Buddhist calendar | 1190 |
| Burmese calendar | 8 |
| Byzantine calendar | 6154–6155 |
| Chinese calendar | 乙巳年 (Wood Snake) 3343 or 3136 — to — 丙午年 (Fire Horse) 3344 or 3137 |
| Coptic calendar | 362–363 |
| Discordian calendar | 1812 |
| Ethiopian calendar | 638–639 |
| Hebrew calendar | 4406–4407 |
| Hindu calendars | |
| - Vikram Samvat | 702–703 |
| - Shaka Samvat | 567–568 |
| - Kali Yuga | 3746–3747 |
| Holocene calendar | 10646 |
| Iranian calendar | 24–25 |
| Islamic calendar | 25–26 |
| Japanese calendar | Taika 2 (大化２年) |
| Javanese calendar | 537–538 |
| Julian calendar | 646 DCXLVI |
| Korean calendar | 2979 |
| Minguo calendar | 1266 before ROC 民前1266年 |
| Nanakshahi calendar | −822 |
| Seleucid era | 957/958 AG |
| Thai solar calendar | 1188–1189 |
| Tibetan calendar | 阴木蛇年 (female Wood-Snake) 772 or 391 or −381 — to — 阳火马年 (male Fire-Horse) 773 or 392 or −380 |
Year 646 (DCXLVI) was a common year starting on Sunday (link will display the full calendar) of the Julian calendar. The denomination 646 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.