644 BC

644 BC in various calendars
Gregorian calendar	644 BC; DCXLIV BC
Ab urbe condita	110
Ancient Egypt era	XXVI dynasty, 21
- Pharaoh	Psamtik I, 21
Ancient Greek era	34th Olympiad (victor)¹
Assyrian calendar	4107
Balinese saka calendar	N/A
Bengali calendar	−1236
Berber calendar	307
Buddhist calendar	−99
Burmese calendar	−1281
Byzantine calendar	4865–4866
Chinese calendar	丙子年 (Fire Rat); 2054 or 1847; — to —; 丁丑年 (Fire Ox); 2055 or 1848
Coptic calendar	−927 – −926
Discordian calendar	523
Ethiopian calendar	−651 – −650
Hebrew calendar	3117–3118
Hindu calendars
- Vikram Samvat	−587 – −586
- Shaka Samvat	N/A
- Kali Yuga	2457–2458
Holocene calendar	9357
Iranian calendar	1265 BP – 1264 BP
Islamic calendar	1304 BH – 1303 BH
Javanese calendar	N/A
Julian calendar	N/A
Korean calendar	1690
Minguo calendar	2555 before ROC; 民前2555年
Nanakshahi calendar	−2111
Thai solar calendar	−101 – −100
Tibetan calendar	阳火鼠年; (male Fire-Rat); −517 or −898 or −1670; — to —; 阴火牛年; (female Fire-Ox); −516 or −897 or −1669

Millennium:	1st millennium BC
Centuries:	8th century BC; 7th century BC ; 6th century BC;
Decades:	660s BC; 650s BC; 640s BC ; 630s BC; 620s BC;
Years:	647 BC; 646 BC; 645 BC; 644 BC ; 643 BC; 642 BC; 641 BC;

The year 644 BC was a year of the pre-Julian Roman calendar. In the Roman Empire, it was known as year 110 Ab urbe condita. The denomination 644 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.

Gregorian calendar	644 BC DCXLIV BC
Ab urbe condita	110
Ancient Egypt era	XXVI dynasty, 21
- Pharaoh	Psamtik I, 21
Ancient Greek era	34th Olympiad (victor )¹
Assyrian calendar	4107
Balinese saka calendar	N/A
Bengali calendar	−1236
Berber calendar	307
Buddhist calendar	−99
Burmese calendar	−1281
Byzantine calendar	4865–4866
Chinese calendar	丙子年 (Fire Rat) 2054 or 1847 — to — 丁丑年 (Fire Ox) 2055 or 1848
Coptic calendar	−927 – −926
Discordian calendar	523
Ethiopian calendar	−651 – −650
Hebrew calendar	3117–3118
Hindu calendars
- Vikram Samvat	−587 – −586
- Shaka Samvat	N/A
- Kali Yuga	2457–2458
Holocene calendar	9357
Iranian calendar	1265 BP – 1264 BP
Islamic calendar	1304 BH – 1303 BH
Javanese calendar	N/A
Julian calendar	N/A
Korean calendar	1690
Minguo calendar	2555 before ROC 民前2555年
Nanakshahi calendar	−2111
Thai solar calendar	−101 – −100
Tibetan calendar	阳火鼠年 (male Fire-Rat) −517 or −898 or −1670 — to — 阴火牛年 (female Fire-Ox) −516 or −897 or −1669