The sexagenary cycle — the great wheel of sixty years
The Imjin War, the Gabo Reform, the Byeongja invasion — Korean history is written in Stem-and-Branch
A story to start
The Imjin War, the Byeongja invasion, the Gapsin coup, the Gabo Reform, the Eulmi incident, the Gyeongsul annexation. The first two syllables of every event Koreans memorise in history class are that year’s Stem-and-Branch pairing. The war of the Imjin year, the reform of the Gabo year. To people then, the pairing simply was how you wrote a year. Today we learn what that notation is — the sexagenary cycle.
📖 The main point — why sixty?
Pair the ten Stems and twelve Branches in order: Gap+Ja = Gapja, Eul+Chuk = Eulchuk, Byeong+In = Byeong-in… The Stems go round ten times, the Branches twelve, and at exactly the sixtieth they return to Gapja (the lowest common multiple of 10 and 12). Those sixty combinations are the cycle. One important rule: yang Stems pair only with yang Branches, yin only with yin. So combinations like “Gapchuk” or “Eulja” do not exist. Say a pairing that isn’t in the sixty and you can spot a fake master on the spot.
🔍 In practice — converting a year
Here is the practical formula. Subtract 4 from the Gregorian year; the remainder on division by 10 gives the Stem (0 = Gap, 1 = Eul, 2 = Byeong…), and the remainder on division by 12 gives the Branch (0 = Ja, 1 = Chuk, 2 = In…). Take 2026: 2026 − 4 = 2022. 2022 ÷ 10 leaves 2 → Byeong. 2022 ÷ 12 leaves 6 → O. So 2026 is a Byeong-o year. Byeong is Fire and O is Fire — fire on fire, which is why it is called the year of the Red Horse. Run your own birth year through it and check against this site’s result.
🗣️ The story people tell
The Korean sixtieth-birthday celebration, <i>hwangap</i>, means “the Gapja has returned” — the day you meet the pairing of your birth year again after sixty years. When lifespans were short, completing one full lap of the calendar of a life was a village occasion. Sixty is youthful now and the parties have quietened, but the Myeongri meaning holds: from sixty-one you begin living through years with the same pairings as when you were born. A second run.
🧭 Working through the situations
Here is the practical trick for doing year pairings in your head. Memorise one anchor — 2020 is Gyeongja. From there move one Stem and one Branch per year: 2021 Sinchuk, 2022 Imin, 2023 Gyemyo, 2024 Gapjin, 2025 Eulsa, 2026 Byeong-o. Backwards the same — 2019 Gihae, 2018 Musul. Answer “what year were you born?” with the pairing over drinks and you get a reaction. Also, a chart sometimes carries the same pairing twice (year pillar and day pillar both Gapja, say) — that is called an echo, and reads as that energy emphasised doubly.
❓ Frequently asked
Q. Why is the sixtieth-birthday celebration at 61, not 60? Because in the Korean counting system where the year of birth is age one, the pairing of your birth year returns on your 60th birthday by international count. Someone born in a Gapja year meets Gapja again at Korean age 61. Q. When my animal’s year comes round every twelve years, is that lucky? Myeongri actually treats it cautiously. A year carrying the same character as your year Branch is a year of doubled energy, so presence grows and so do competition and depletion (it connects to the Friend-year concept on the annual tab). Q. If Byeong-o is a horse year, why the “red” horse? Because the Stem Byeong is Fire energy and red is Fire’s colour. On the same principle 2026 Byeong-o is the Red Horse and 2027 Jeongmi the Red Sheep.
✏️ Today’s one step
Use the formula to work out this year, next year and your birth year, then check against the site. Bonus: work out which year is your parents’ sixtieth (birth year + 60) and name its pairing.