645 BC

Millennium: 1st millennium BC
Centuries:
Decades:
Years:
645 BC in various calendars
Gregorian calendar645 BC
DCXLV BC
Ab urbe condita109
Ancient Egypt eraXXVI dynasty, 20
- PharaohPsamtik I, 20
Ancient Greek era33rd Olympiad, year 4
Assyrian calendar4106
Balinese saka calendarN/A
Bengali calendar−1237
Berber calendar306
Buddhist calendar−100
Burmese calendar−1282
Byzantine calendar4864–4865
Chinese calendar乙亥年 (Wood Pig)
2053 or 1846
    — to —
丙子年 (Fire Rat)
2054 or 1847
Coptic calendar−928 – −927
Discordian calendar522
Ethiopian calendar−652 – −651
Hebrew calendar3116–3117
Hindu calendars
 - Vikram Samvat−588 – −587
 - Shaka SamvatN/A
 - Kali Yuga2456–2457
Holocene calendar9356
Iranian calendar1266 BP – 1265 BP
Islamic calendar1305 BH – 1304 BH
Javanese calendarN/A
Julian calendarN/A
Korean calendar1689
Minguo calendar2556 before ROC
民前2556年
Nanakshahi calendar−2112
Thai solar calendar−102 – −101
Tibetan calendar阴木猪年
(female Wood-Pig)
−518 or −899 or −1671
    — to —
阳火鼠年
(male Fire-Rat)
−517 or −898 or −1670

The year 645 BC was a year of the pre-Julian Roman calendar. In the Roman Empire, it was known as year 109 Ab urbe condita . The denomination 645 BC 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.