Mayan Calendar Calculator — Long Count, Tzolk'in & Haab
Enter any Gregorian date and instantly see its Mayan Long Count (b'ak'tun.k'atun.tun.winal.k'in), the 260-day Tzolk'in sacred date, and the 365-day Haab solar date — all computed using the accepted GMT correlation constant.
How does this calculator work?
Convert a Gregorian date to the Mayan Long Count by computing the Julian Day Number, subtracting the GMT constant 584283, then dividing by 144 000 (baktuns), 7 200 (katuns), 360 (tuns), 20 (uinals), and 1 (kins). The Tzolk'in and Haab are found by taking the day count modulo 260 and 365 respectively, with fixed offsets anchored to the epoch date 4 Ajaw 8 Kumk'u.
Formula
How this is calculated
The Maya used three interlocking calendar systems simultaneously. The Long Count is an absolute count of days since the mythological creation date (August 11, 3114 BCE in the proleptic Gregorian calendar under the GMT correlation). It is written as five positional numbers: baktun.katun.tun.uinal.kin, where 1 kin = 1 day, 1 uinal = 20 kin, 1 tun = 18 uinals (360 days), 1 katun = 20 tuns (7 200 days) and 1 baktun = 20 katuns (144 000 days). The most famous date, 13.0.0.0.0, fell on December 21, 2012 — the end of the 13th baktun, widely misunderstood as a prophecy.
The Tzolk'in is a 260-day sacred cycle formed by combining a number (1–13) and one of 20 named days. Both the number and the name advance by one each day, cycling independently. The epoch date 0.0.0.0.0 corresponds to '4 Ajaw' in the Tzolk'in. The Haab is a 365-day solar approximation with 18 named months of 20 days plus a 5-day closing period called Wayeb. The epoch corresponds to '8 Kumk'u' in the Haab.
This calculator uses the GMT (Goodman-Martínez-Thompson) correlation constant 584283, which is the scholarly consensus linking the Long Count to the Julian Day Number system. The calculation converts the Gregorian date to a Julian Day Number, subtracts the correlation constant, and then maps the result to the three calendar systems. Dates before the Mayan epoch (~3114 BCE) are not supported.
Frequently asked questions
The Long Count is written as baktun.katun.tun.uinal.kin. Read it like a base-20 odometer (with one irregular step: tun = 18 uinals). Each kin is 1 day; a full baktun spans 144 000 days (~394 years). The 14th baktun (14.0.0.0.0) began on December 21, 2012 and will end around October 13, 2406.
Several correlation constants have been proposed by scholars. GMT (584283) is the academic consensus, confirmed by matching historical records of Maya astronomical observations (notably Venus cycles) with independently dated colonial-era documents. It places the Creation date at August 11, 3114 BCE (proleptic Gregorian).
The Long Count completed its 13th baktun (13.0.0.0.0), a milestone the Classic Maya commemorated on monuments but which carried no apocalyptic meaning in authentic Maya belief. The 14th baktun simply began on December 22, 2012, as later inscriptions (e.g. Palenque's Tortuguero Monument 6) confirm.
Also known as
TG we-Calculate Editorial Team. (2026). Mayan Calendar Calculator — Long Count, Tzolk'in & Haab [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/mayan-calendar-calculator
TG we-Calculate Editorial Team. "Mayan Calendar Calculator — Long Count, Tzolk'in & Haab." TG we-Calculate. 2026. https://we-calculate.com/calculator/mayan-calendar-calculator.
TG we-Calculate Editorial Team, "Mayan Calendar Calculator — Long Count, Tzolk'in & Haab," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/mayan-calendar-calculator
@misc{wecalculate_mayan_calendar_calculator, title = {Mayan Calendar Calculator — Long Count, Tzolk'in & Haab}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/mayan-calendar-calculator}}, year = {2026}, note = {TG we-Calculate} }
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