--- title: "16×16 Sudoku: Rules and How to Start | Sudoku Flow" description: "16×16 Sudoku uses sixteen symbols, often 1 to 9 and A to G, in 16 rows, 16 columns and 16 boxes of 4×4. The rules, first moves on a real puzzle and tips." url: https://sudokuflow.com/guides/16x16-sudoku-rules/ language: en last_modified: 2026-11-06 --- [Sudoku guides](https://sudokuflow.com/guides/) # 16×16 Sudoku: Rules and How to Start 16×16 Sudoku uses sixteen symbols, often 1 to 9 and A to G, in 16 rows, 16 columns and 16 boxes of 4×4. The rules, first moves on a real puzzle and tips. Updated 2026-11-06 ## Quick answer A 16×16 Sudoku has 256 squares in 16 rows, 16 columns and 16 boxes of 4×4. Every row, column and box must hold each of 16 symbols exactly once. Our printable sheets use 1 to 9 and then A to G. The rules and the solving steps are the same as in a 9×9 Sudoku; there are just more of them. - 256 squares: 16 rows, 16 columns and 16 boxes of 4×4. - Every row, column and box holds each of the 16 symbols once. - Letters are only symbols: no letter stands for a number. - The singles you know from 9×9 get you started. - Our Easy 16×16 sheets need only squares with one symbol left. ## The rules Fill the grid so that every row, every column and every 4×4 box holds each of the 16 symbols exactly once. As in a 9×9 Sudoku, a good puzzle has exactly one answer. ## Which symbols? There is no single standard. Our printable sheets use 1 to 9 and then A to G. You will also see 0 to 9 with A to F, as in hexadecimal numbers, or the numbers 1 to 16 with two digits in some squares. Whichever set a puzzle uses, the symbols are only names: no arithmetic is involved. ## The first moves on a real puzzle This is the first Easy sheet from our printable 16×16 Sudoku, with 102 symbols given. The 5 marked squares are the first moves a beginner would find, in this order: ```text . . . 5 | 9 G . C | 6 D F 3 | . . 1 7 . . . . | 4 . . . | G . . B | . . E . . . B G | . 2 E . | . . 7 1 | . . . 3 4 . . . | . 6 . . | 2 5 A E | 9 . . . --------+---------+---------+-------- 5 . 2 . | G C . . | D 3 . . | 8 1 . . . B . . | . 5 . . | . 1 . 7 | 6 . 3 . D . 6 . | . 1 . . | . B . . | . . A . 8 . . . | . . . . | . . . . | . . . . --------+---------+---------+-------- F . 3 6 | . . 1 8 | 9 . . . | . 2 5 E A 5 . 2 | . 9 . G | . . . . | 7 . . . B . . 9 | . A . 2 | . . . 8 | . F . . 7 8 . 4 | 3 . D . | A 2 . . | B 9 . C --------+---------+---------+-------- 1 . 8 . | D 3 . F | . A . . | . . . G . 2 . . | . . G . | . F . 6 | . . . . . 6 D . | . 7 . 4 | . . C G | E . 2 5 . 9 . B | 5 . . . | . . 8 4 | D 3 . 6 ``` *16×16 Sudoku, Easy, sheet 1: the first 5 moves are marked.* 1. **Row 1, column 6: G**. G has only one place left in its box. 2. **Row 4, column 12: E**. E has only one place left in its box. 3. **Row 10, column 4: 2**. 2 has only one place left in its box. 4. **Row 11, column 1: B**. B has only one place left in its box. 5. **Row 9, column 4: 6**. 6 has only one place left in its box. [Printable 16×16 Sudoku →](https://sudokuflow.com/printables/sudoku-16x16/) ## Tips - Work one symbol at a time: pick it, then look at each box for the places it can still go. - Count what is missing: a row with 14 symbols placed has only two left to find. - Keep notes small. With up to 16 candidates, a square fills up fast. - Write clearly on paper: B and 8, or G and 6, are easy to mix up. - If this is your first giant grid, start with our Easy sheets: they need only squares with one symbol left. [Printable 16×16 Sudoku →](https://sudokuflow.com/printables/sudoku-16x16/) ## Practice Every Find the Mistake puzzle on this site has exactly one wrong digit, and you can play each board right on its page. [Play the puzzles →](https://sudokuflow.com/puzzles/) ## Sudoku guides - [How to Find a Mistake in Sudoku](https://sudokuflow.com/guides/find-a-mistake/) - [7 Common Sudoku Mistakes and How to Avoid Them](https://sudokuflow.com/guides/common-mistakes/) - [Why Won't My Sudoku Solve? A Checklist](https://sudokuflow.com/guides/sudoku-wont-solve/) - [Naked Single vs Hidden Single](https://sudokuflow.com/guides/naked-single-vs-hidden-single/) - [Pointing Pair vs Box/Line Reduction](https://sudokuflow.com/guides/pointing-pair-vs-box-line-reduction/) - [X-Wing vs Swordfish](https://sudokuflow.com/guides/x-wing-vs-swordfish/) - [How to Start a Sudoku: The First Five Minutes](https://sudokuflow.com/guides/how-to-start-sudoku/) - [Stuck on a Hard or Expert Sudoku? The Technique You Need Next](https://sudokuflow.com/guides/stuck-on-hard-sudoku/) - [Sudoku Tips That Actually Work (and Is There a Formula?)](https://sudokuflow.com/guides/sudoku-tips/) - [How to Teach a Child Sudoku: 4×4, Then 6×6, Then 9×9](https://sudokuflow.com/guides/teach-kids-sudoku/) - [Can Every Sudoku Be Solved Without Guessing?](https://sudokuflow.com/guides/solve-without-guessing/) - [Which Sudoku Techniques Do You Actually Need? 60,000 Puzzles Counted](https://sudokuflow.com/guides/sudoku-techniques-you-need/) - [How to Solve Sudoku Faster](https://sudokuflow.com/guides/solve-sudoku-faster/) - [Do the Diagonals Count in Sudoku? 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Times by Level](https://sudokuflow.com/guides/how-long-does-sudoku-take/) - [How to Make a Sudoku Puzzle, by Hand or by Program](https://sudokuflow.com/guides/how-to-make-a-sudoku/) - [Sudoku Notes: When and How to Use Pencil Marks](https://sudokuflow.com/guides/sudoku-notes-pencil-marks/) - [Sudoku for Seniors: Large Print Puzzles and How to Start](https://sudokuflow.com/guides/large-print-sudoku-for-seniors/) - [Wordoku: Sudoku with Letters Instead of Numbers](https://sudokuflow.com/guides/wordoku-letter-sudoku/) - [What each Sudoku difficulty level asks of you](https://sudokuflow.com/data/sudoku-difficulty-levels/) - [Sudoku facts](https://sudokuflow.com/guides/sudoku-facts/) - [Sudoku checker](https://sudokuflow.com/tools/sudoku-checker/) - [Sudoku for kids](https://sudokuflow.com/printables/kids/) - [Find the Mistake Sudoku](https://sudokuflow.com/find-the-mistake/) ![Sudoku app icon](https://sudokuflow.com/assets/app-icon.png) ## Want more boards like this? We also make a Sudoku app for iPhone, iPad, Mac and Android. There are no ads in it at all, it works offline, and when you ask for a hint it shows you the technique instead of just filling in a number. [App Store iPhone, iPad, Mac](https://apps.apple.com/app/apple-store/id6502922368?pt=125379530&ct=sudokuflow_web&mt=8) [Google Play Android](https://play.google.com/store/apps/details?id=com.rubigogames.sudoku&referrer=utm_source%3Dsudokuflow%26utm_medium%3Dweb%26utm_campaign%3Dsite) Sudoku Flow is made by Rubigo Games, the developer of the Sudoku app recommended on this site.