Riichi Calc is an easy to use app that takes any valid Japanese mahjong hand and calculates all possible winning combinations. A great companion for any Japanese mahjong player! Feel free to e-mail me about any calculation errors. Features: 　• Used for the Japanese variant of Mahjong 　• Order is irrelevant. The app will rearrange the tiles for you 　• Determine waits of a tenpai hand 　• Provides warnings against illegal combinations (e.g. riichi with an open hand) 　• Calculate points using han and fu as the input 　• Display terminology in English or romanized Japanese