About — Mahjong Calculator

Mahjong Calculator is a free, in-browser tool for scoring a mahjong hand. You tap tiles to build your hand, watch your shanten count and waits update live, then get a full breakdown of every scoring pattern the moment the hand wins — no sign-up, no app to install, and no tile data ever leaves your device.

Mahjong is not one game but a family of regional games that each score completely differently. This calculator covers the five variants people actually sit down and play:

Riichi (Japanese) — han + fu scoring with riichi declarations, dora, and yakuman caps.
Hong Kong (Cantonese) — the casual faan system with exponential 2^faan payouts.
Taiwanese (16-tile) — five melds plus a pair, scored in tai.
MCR (Chinese Official) — the 81-fan tournament standard used at world championships.
Sichuan (Bloody Battle) — no honors, no chi, mandatory missing-suit play.

Each variant has its own dedicated page with the calculator, the full scoring rules, a worked example, and a reference list of every yaku, fan, faan, or tai pattern. There's also a mahjong glossary and side-by-side variant comparisons if you're trying to figure out how two rule sets differ.

It's built for the player who already knows roughly how the game works but wants the math done correctly and fast — settling a scoring dispute at the table, double-checking a hand from an online match, or learning a new variant. Because every hand state is encoded in the page URL, you can copy a link and share the exact hand with someone else.

Mahjong Calculator is made by Valin Studio, an independent studio building small, focused web tools that do one thing well and stay free to use. The calculator is supported by ads on the page; if it saved you an argument at the table, you can buy us a coffee.