Mahjong Shanten Calculator | Wait & Ukeire Auto-detection

Enter your mahjong hand to instantly compute shanten count, waiting tiles, and ukeire (accepting tiles) for standard hand, chiitoitsu, and kokushi musou. Enter 14 tiles to compare efficiency across discards. The hand is encoded in the URL so you can share it directly.

Hand

0 tiles

Click tiles below to input

What is shanten?

Shanten is the minimum number of tile exchanges still required to reach tenpai. 0-shanten = tenpai, -1 = winning hand, and 1+ is called n-shanten. It is the most fundamental indicator for discard selection and push/fold decisions in mahjong.

Calculation (standard hand)

The basic formula:

shanten = 8 − sets × 2 − partials − pairs
  • set = a sequence (123m etc.) or a triplet (222p etc.)
  • partial = ryanmen (34m), kanchan (35m), or penchan (12m) — a 2-tile proto-set
  • pair = two identical tiles (1m1m etc.)
  • sets + partials cap at 4; only one pair is counted as the head candidate

Chiitoitsu / Kokushi musou

Chiitoitsu shanten
6 − pairs; identical tiles past the second copy do not contribute.
Kokushi musou shanten
13 − distinct yaochuhai − (1 if any yaochuhai pair exists). Yaochuhai = the 13 terminals and honors.

The tool computes all three forms simultaneously and reports the minimum as the displayed shanten.

How to use

  1. Click tiles on the panel or type your hand as text
  2. Click "Analyze Tile Efficiency"
  3. Shanten is shown for standard hand, chiitoitsu, and kokushi musou
  4. With 13 tiles, see ukeire (tiles that advance shanten when drawn). With 14 tiles, see post-discard shanten for each candidate.
  5. The URL after analysis encodes the hand, so you can copy and share it.

Text input format

You can enter a hand using:

  • 123m → 1-2-3 of characters (man)
  • 456p → 4-5-6 of dots (pin)
  • 789s → 7-8-9 of bamboo (sou)
  • 1234567z → honor tiles (East/South/West/North/White/Green/Red)

Example: 123m456p789s1112z

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