Riichi Mahjong Calculator
Calculate your hand’s score based on Fu, Han, and other game variables.
The number of yaku (scoring elements) in your hand. Does not include Dora.
The mini-points for melds, waits, and win type. Must be rounded to the nearest 10.
Total bonus tiles, including red fives, ura-dora, and kan-dora.
Number of repeat counters on the table.
What is a Riichi Mahjong Calculator?
A Riichi Mahjong calculator is an essential tool for players of the Japanese variant of mahjong. Scoring in Riichi Mahjong is notoriously complex, involving two key variables: Han (飜) and Fu (符). This calculator automates the process, removing the need for manual table lookups and complex calculations. By inputting the Han, Fu, Dora, and other situational factors, a player can quickly determine the exact point value of a winning hand. This is crucial for both casual home games and more serious play, ensuring scoring is accurate and fast. The use of a riichi mahjong calculator helps players focus on strategy rather than getting bogged down in arithmetic.
The Riichi Mahjong Scoring Formula and Explanation
The core of Riichi Mahjong scoring is the calculation of “Basic Points.” For hands that are not limit hands (less than 5 Han), the formula is:
Basic Points = Fu × 2(2 + Han)
This “Basic Points” value is then rounded up to the nearest hundred. The final payment depends on the winner’s status (Dealer or Non-Dealer) and the win type (Ron or Tsumo). However, this formula is capped. If the calculated Basic Points exceed 2000, the hand is capped at a “Mangan” and is worth a flat 2000 Basic Points. For hands with 5 or more Han, Fu becomes irrelevant and the hand value is determined by a set limit.
Variables Table
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| Han (飜) | The primary score multiplier, based on the winning patterns (Yaku) in a hand. | Han | 1 – 13+ |
| Fu (符) | Mini-points awarded for the hand’s structure: melds, pair, and wait type. | Fu | 20 – 110 |
| Dora (ドラ) | Bonus tiles that each add 1 Han to the hand’s value. They are not Yaku. | Han | 0 – 10+ |
| Honba (本場) | Counters for draws or dealer wins, adding a bonus to the next win. | Points (300 per counter) | 0 – 5+ |
Limit Hands (Yakuman)
When the Han count reaches certain thresholds, the scoring simplifies to set values, making the Fu count irrelevant. This prevents scores from becoming astronomically high. Our riichi mahjong calculator handles these automatically.
| Han Count | Hand Name | Basic Points | Non-Dealer Ron | Dealer Ron |
|---|---|---|---|---|
| 5 | Mangan | 2,000 | 8,000 | 12,000 |
| 6-7 | Haneman | 3,000 | 12,000 | 18,000 |
| 8-10 | Baiman | 4,000 | 16,000 | 24,000 |
| 11-12 | Sanbaiman | 6,000 | 24,000 | 36,000 |
| 13+ | Kazoe Yakuman | 8,000 | 32,000 | 48,000 |
Practical Examples
Example 1: Simple Non-Dealer Win
A non-dealer wins by Ron with a common hand.
- Inputs: 2 Han, 40 Fu, 1 Dora, 0 Honba.
- Calculation: Total Han is 3. Basic points are 40 × 2(2 + 3) = 40 x 32 = 1280. Rounded up, this is 1300.
- Results: As a non-dealer Ron, the payment is 4 × 1300 Basic Points = 5200 points from the discarder.
Example 2: Dealer Tsumo with a Limit Hand
The dealer wins by Tsumo with a valuable hand.
- Inputs: 4 Han, 30 Fu, 2 Dora, 1 Honba.
- Calculation: Total Han is 6. This is a Haneman limit hand, so Fu is ignored. Basic Points are 3,000.
- Results: As a dealer Tsumo, each non-dealer pays 2 × 3,000 = 6,000 points. Additionally, 1 Honba counter adds 100 points from each player. Total payment is 6,100 from each of the three players, for a total of 18,300 points.
How to Use This Riichi Mahjong Calculator
- Enter Han: Input the total Han from the Yaku in your hand. Do not include Dora here.
- Enter Fu: Input the Fu value for your hand, rounded up to the nearest 10. (e.g., 32 Fu becomes 40). A standard closed ron is 30 Fu, Pinfu tsumo is 20 Fu.
- Enter Dora: Input the total number of all Dora tiles (regular, red, ura, kan).
- Enter Honba: Add any Honba counters on the table.
- Select Player & Win Type: Choose whether the winner is the Dealer or a Non-Dealer, and whether the win was by Ron or Tsumo.
- Calculate: Click the “Calculate Score” button to see the results instantly. The results will show the hand’s name (e.g., Mangan), the basic points, the payment breakdown, and the total points transferred.
Key Factors That Affect a Riichi Mahjong Score
- Han: The most significant factor. Each additional Han roughly doubles the hand’s value until limit hands are reached.
- Fu: Important for smaller hands (1-4 Han). Higher Fu can push a hand into the next point bracket, significantly increasing its value.
- Dealer Status (Oya): The dealer (Oya) receives approximately 50% more points on a win compared to a non-dealer (Ko). They also pay more if they lose.
- Win Method (Ron vs. Tsumo): A Ron win is paid entirely by the discarding player. A Tsumo win splits the payment among the other three players, which can sometimes result in a slightly higher total payout due to rounding.
- Dora: A quick way to increase Han value, but they do not count as Yaku, so you still need at least one Yaku to win.
- Riichi Bet: A successful Riichi adds 1 Han and gives access to Ura-Dora, potentially increasing the score dramatically. The 1,000 point Riichi stick also goes to the winner.
Frequently Asked Questions (FAQ)
What is the minimum Fu a hand can have?
A hand always starts with a base of 20 fu (fūtei). The exception is an open Pinfu-style hand, which is not allowed in most rules, and a seven-pairs hand which is fixed at 25 Fu. The lowest valid scoring hand is typically 30 fu 1 han.
Why is my 4 Han, 30 Fu hand a Mangan?
In many rulesets, a 4 Han 30 Fu hand and a 3 Han 60 Fu hand are rounded up to Mangan (8,000 for non-dealer ron) because their calculated scores are very close to the Mangan value. This riichi mahjong calculator applies this common rule.
What is a “Kazoe Yakuman”?
A Kazoe Yakuman (Counted Yakuman) is a non-special hand whose Han total is 13 or more. It is scored the same as a regular Yakuman (e.g., 32,000 for non-dealer ron).
Do I need to calculate Fu for a 5 Han hand?
No. Once a hand reaches 5 Han, it automatically becomes a Mangan (or higher), and the Fu count is no longer relevant for scoring.
How are Honba points calculated?
Each Honba counter on the table adds 300 points to the total value of the winning hand. For a Ron win, the discarder pays the extra 300 points. For a Tsumo win, each of the three losers pays an extra 100 points.
Can I win without a Yaku?
No. A winning hand must contain at least one Yaku (scoring pattern). Dora and Red Fives add Han value but do not count as Yaku.
What is the difference between this calculator and a Fu calculator?
This riichi mahjong calculator determines the final point value based on Han and Fu. A Fu calculator is a different tool used to determine the Fu value itself by analyzing the specific melds, pair, and wait of a hand.
What does “rounding up to the nearest 100” mean?
After the payment multipliers are applied to the basic points (e.g., non-dealer tsumo where dealer pays 2x basic points and others pay 1x), each individual payment is rounded up. For example, a payment of 1280 points becomes 1300.
Related Tools and Internal Resources
For more in-depth mahjong analysis, check out our other tools and guides:
- Complete Yaku Chart – A comprehensive list of all yaku for beginners and experts.
- Riichi Mahjong Fu Calculator – A tool to help you calculate the precise Fu value of your hand.
- Shanten Calculator – Find out how many tiles away your hand is from being ready to win (tenpai).
- Tile Efficiency Trainer – Improve your game by learning the best discards.
- Beginner’s Strategy Guide to Riichi Mahjong – Learn the fundamentals of offense and defense.
- Glossary of Mahjong Terms – Understand all the jargon used in the game.