Interactive calendar mathematics
Maya Time Units
Calculator
Combine baktun, katun, tun, uinal, and k’in as quantities—or unfold a total number of days into the five Long Count units.
01 Enter quantities
Add units together
Each field accepts a quantity from 0 to 999,999. Values do not need to be normalized.
01 Enter a duration
Decompose total days
Enter a non-negative whole number through 999,999,999,999 days.
Katun and tun positions use 0–19; uinal uses 0–17; k’in uses 0–19. Baktun holds the remaining whole cycles.
02 Read the result
≈ 1,268.01 tropical years
baktun · katun · tun · uinal · k’in
(3 × 144,000) + (4 × 7,200) + (6 × 360) + (8 × 20) + (10 × 1) = 463,130 days
Unit hierarchy
From one day to a baktun
The system is mostly vigesimal. Its calendar-specific exception is the tun: 18 uinal make 360 days, rather than 20 uinal making 400.
K’in
1 dayThe base day and smallest unit used here.
Uinal
20 daysTwenty k’in form one uinal.
Tun
360 daysEighteen uinal form one tun.
Katun
7,200 daysTwenty tun form one katun.
Baktun
144,000 daysTwenty katun form one baktun.
Scope of this tool
Duration arithmetic, not a calendar date
This calculator adds and decomposes durations. It does not apply a calendar correlation, produce Tzolk’in or Haab positions, or convert the result to a Gregorian date.
Need a dated Long Count calculation? Open Tool #3Evidence & methodology