| Millennium: | 1st millennium |
|---|---|
| Centuries: | 8th century – 9th century – 10th century |
| Decades: | 780s 790s 800s – 810s – 820s 830s 840s |
| Years: | 815 816 817 – 818 – 819 820 821 |
| 818 by topic | |
| Politics | |
| State leaders – Sovereign states | |
| Birth and death categories | |
| Births – Deaths | |
| Establishment and disestablishment categories | |
| Establishments – Disestablishments | |
| Gregorian calendar | 818 DCCCXVIII |
| Ab urbe condita | 1571 |
| Armenian calendar | 267 ԹՎ ՄԿԷ |
| Bahá'í calendar | -1026 – -1025 |
| Bengali calendar | 225 |
| Berber calendar | 1768 |
| Buddhist calendar | 1362 |
| Burmese calendar | 180 |
| Byzantine calendar | 6326 – 6327 |
| Chinese calendar | 丁酉年十一月廿一日 (3454/3514-11-21) — to —
戊戌年十二月初一日(3455/3515-12-1) |
| Coptic calendar | 534 – 535 |
| Ethiopian calendar | 810 – 811 |
| Hebrew calendar | 4578 – 4579 |
| Hindu calendars | |
| - Bikram Samwat | 874 – 875 |
| - Shaka Samvat | 740 – 741 |
| - Kali Yuga | 3919 – 3920 |
| Holocene calendar | 10818 |
| Iranian calendar | 196 – 197 |
| Islamic calendar | 202 – 203 |
| Japanese calendar | |
| Korean calendar | 3151 |
| Thai solar calendar | 1361 |