# Printable Classic Sudoku — Letter

> Free printable classic sudoku formatted for Letter paper (8.5 × 11 in). Each puzzle uses a 9×9 grid with 30–35 given clues and takes about 15–25 min to solve. Download the PDF and print at 100% scale for correctly sized cells.

Source: https://sudokupuzzlepdf.com/classic-sudoku-puzzle/
Last updated: 2026-08-11

## Key facts

- **Format:** Classic Sudoku
- **Paper size:** Letter (8.5 × 11 in)
- **Grid size:** 9×9
- **Given clues:** 30–35
- **Typical solve time:** 15–25 min
- **Best for:** Traditionalists
- **Techniques required:** scanning, hidden singles, naked pairs, X-Wing (varies by difficulty within the classic format)
- **Solution:** Exactly one, reachable by logic
- **Price:** Free — no signup, no watermark

## How to Print Classic Sudoku on Letter Paper

Letter measures 8.5 × 11 in (215.9 × 279.4 mm) and is the North American standard used in the US and Canada. Standard US letter prints 6 puzzles per page in a clean grid. Set the paper size to Letter in the generator, print at 100% scale rather than Fit to page, and the cells come out at the size they were designed for. Every puzzle has a guaranteed unique solution.

### Why Print Classic Sudoku on Letter?

Letter is the North American standard used in the US and Canada — choose this size when printing on local stationery, or to fit standard binders and folders. Dimensions: **8.5 × 11 in (215.9 × 279.4 mm)**.

Standard US letter prints 6 puzzles per page in a clean grid.

### About Classic Sudoku

Classic Sudoku uses a standard 9×9 grid divided into nine 3×3 regions. Each puzzle has a single unique solution reachable through logical deduction without guessing. The classic format spans all difficulty levels.

Grid: **9×9**. Clue count: **30–35**.

[Read the full classic sudoku guide](https://sudokupuzzlepdf.com/classic-sudoku-puzzle/) or [open the live generator](https://sudokupuzzlepdf.com/classic-sudoku-puzzle-pdf/).

### How to Solve Classic Sudoku — Quick Walkthrough

Classic solving combines all techniques depending on difficulty calibration. Begin with row-by-row scanning for naked singles. Move to column-by-column. Finish with box-by-box. If unresolved cells remain, escalate to hidden singles, then candidate notation if needed.

### Tips for Classic Sudoku Solvers

- Treat Classic Sudoku as a difficulty calibration rather than a unique format. Adjust your strategy based on the clue count: 36+ clues use Easy techniques, 30–35 use Medium, below 30 use Hard.
- Newspaper Classic puzzles typically sit at Medium difficulty. Use hidden singles and naked pairs as your primary techniques.
- Practice mental scanning on Classic Sudoku. The 9×9 format is ideal for building pattern recognition that transfers to all Sudoku variants.
- Solve Classic Sudoku on paper at least once a week. The physical act of scanning a printed grid builds spatial reasoning that on-screen solving cannot replicate.

### Other Paper Sizes

The same classic sudoku is also available in: [A4](https://sudokupuzzlepdf.com/printable-classic-sudoku-a4/) · [Legal](https://sudokupuzzlepdf.com/printable-classic-sudoku-legal/).

### Letter in Other Difficulties

Want a different difficulty on Letter paper? [Easy Sudoku — Letter](https://sudokupuzzlepdf.com/printable-easy-sudoku-letter/) · [Medium Sudoku — Letter](https://sudokupuzzlepdf.com/printable-medium-sudoku-letter/) · [Hard Sudoku — Letter](https://sudokupuzzlepdf.com/printable-hard-sudoku-letter/) · [Expert Sudoku — Letter](https://sudokupuzzlepdf.com/printable-expert-sudoku-letter/) · [Mini Sudoku — Letter](https://sudokupuzzlepdf.com/printable-mini-sudoku-letter/) · [Kids Sudoku — Letter](https://sudokupuzzlepdf.com/printable-kids-sudoku-letter/) · [Large Print Sudoku — Letter](https://sudokupuzzlepdf.com/printable-large-print-sudoku-letter/).

### Classic Sudoku — Letter — Common Questions

#### What makes a Sudoku puzzle 'classic'?

Classic Sudoku refers to the standard 9×9 grid divided into nine 3×3 regions, the format invented by Howard Garns in 1979 and popularised by Japanese puzzle magazines from the 1980s. Classic Sudoku is format-defining rather than difficulty-defining.

#### Can Classic Sudoku be any difficulty?

Yes. The Classic format is independent of difficulty — Classic puzzles can be Easy, Medium, Hard, or Expert depending on clue count and distribution. When solvers say 'Classic Sudoku' they usually mean the standard format at Medium difficulty.

#### How is Classic Sudoku different from variant Sudokus?

Variant Sudokus add extra constraints (diagonal sums, killer cages, X-Sudoku, hyper-Sudoku regions) on top of the standard rules. Classic Sudoku has only the three core constraints: each digit 1–9 must appear exactly once in each row, column, and 3×3 box.

## Generate this puzzle

Free printable PDF generator: https://sudokupuzzlepdf.com/classic-sudoku-puzzle-pdf/