How to Create a Sudoku

Co-authored by wikiHow Staff

Last Updated: March 29, 2023 References Tested

Sudoku is a fun way to pass the time, and it’s even more fun once you learn to make your own puzzles. Creating your own puzzle can be tricky, but it will give you a new appreciation for the game. Make your 9x9 square, then fill in your clues by hand or with the help of an online generator. Once your puzzle is finished, share it with friends or try it out yourself.

Method 1

Method 1 of 3:

Making or Printing Your Grid

1
Gather your materials. To make a Sudoku puzzle, you’ll need a pencil, a marker, a ruler and a sheet of standard printer paper. You’ll use the pencil for the first few steps so that you can erase any mistakes, while the ruler will help keep your grid even.^{[1]
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2
Draw a large square. Using your pencil and ruler, draw a large square. The square should be about 5”x5”, but you can make it larger or smaller if you like. Also, if you have a Sudoku book handy, consider tracing an existing puzzle to get a standard shape and size.^{[2]
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3
Divide the square into a 3x3 grid. Again using your pencil, divide the large outer square into 9 smaller squares. There should be three squares on the top row, three in the middle row and three in the bottom row: three equally spaced lines going across the square, and three equally spaced lines going down the square. Make sure you use a ruler to ensure that your lines are straight.^{[3]
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4
Divide the small squares into 3x3 grids. Once you’ve divided the square into 9 smaller squares, you’ll need to divide those squares into even smaller grids. Using your pencil and ruler, draw three equally spaced lines across each square, then three equally spaced lines down each square. Look at an existing Sudoku puzzle if you need a reference.
5
Trace the pencil lines with marker. It’s easy to rub away pencil, and you don’t want your board to fade away. Trace the lines you drew with a marker or pen, making sure that the lines of the first 3x3 square are thicker and bolder. The lines of the smaller squares should be light and thin, so consider using a ballpoint pen.
6
Copy or scan your blank puzzle. You may want to make more than one Sudoku puzzle, and you can save the hassle of having to redraw the board. Simply scan or photocopy the board and create some duplicates. Use a scanner at home or make a trip to a copy shop or library to use a photocopier.
7
Print out a template. If you don’t want to draw your puzzle-grid by hand, find a template online. Many websites provide grids of different sizes, and you can even find one on this page. Print as many copies of your templates as you think you’ll need.^{[4]
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Method 2

Method 2 of 3:

Creating the Solution

1
Start filling in a solution. Using a pencil, start creating a solution for your puzzle. Work with each number in order so that you can be sure your solution is valid. Don’t forget how the game works, or you’ll end up with an incorrect solution.^{[5]
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- Remember the rules. To win sudoku, the player must fill the grid so that each row contains the number 1-9, each column contains the numbers 1-9 and each 3x3 box contains the numbers 1-9.^{[6]
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- Start filling in the number 1. Place a number one in each 3x3 box, each row and each column. Make sure that that you don’t place two number ones in any column, row or 3x3 box.
- Move on to the number 2. Begin to place the number 2 in each column, row and 3x3 square. As with the number one, make sure you don’t double up your number 2s.
- Continue with each number consecutively. Keep adding the number 3, the number 4 and so on to each row, column and 3x3 box. As you fill in more numbers, the boxes will become easier to fill because you’ll have fewer and fewer spaces left.
2
Backtrack if you get stuck. Creating your solution might become frustrating. You can easily back yourself into a corner, where you’ll find that you can only fill a row or column with a duplicate number. If you end up stuck, erase a few of the problem digits and start the section over again.
3
Double-check your solution. Make sure that your solution is correct by checking for duplicate numbers. It may take a while to go through each 3x3 block, row and column, but make sure that they each contain the numbers 1-9 with no duplicate digits. If you don’t want to do this by hand, use an online Sudoku solver. Once you’re sure it’s right, you’re ready to put on the finishing touches.^{[7]
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4
Use an online generator. If making a Sudoku puzzle by hand gets too frustrating, check out an online generator. You’ll still have the ability to customize the difficulty and the number of clues, but you won’t have to do as much work. There are many different websites that can help you generate and check your puzzles.^{[8]
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Method 3

Method 3 of 3:

Finishing the Puzzle

1
Begin removing digits. With an eraser, begin by erasing one number from each column, row and 3x3 square. The more you erase, the harder the puzzle will be to solve, so think about how difficult you want the puzzle to be. Erase lightly so that if you change your mind, you’ll be able to recover your clues. Also, consider making a copy of your solution to reference.^{[9]
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Check to make sure your puzzle can be solved. With each digit that you erase, work through the puzzle to make sure it can still be finished. Make sure that your player will still be able to use the clues available to fill in the blanks, and that there aren’t spaces with insufficient clues. If you find that it’s too difficult, replace the clues that you erased and try erasing others.
3
Erase blank squares and ink filled ones. Once you’ve finished erasing clues, give each empty square some extra attention with the eraser. If you don’t fully erase the missing squares, your player may be able to see which number was originally there. Then, use your marker to trace the numbers in the filled squares so that they don’t smudge.^{[10]
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- If you want to, copy your finished puzzle onto a new grid so there's no chance of a player seeing your original answers.
4
Copy and share your puzzle. Make some copies of your finished puzzle at home or in a copy shop. Next, share it with your friends and family members. Get some feedback about the difficulty of your puzzle, then practice making a few more.

Sample Sudoku Puzzles

Sample Easy Sudoku

Sample Intermediate Sudoku

Sample Hard Sudoku

Blank Sudoku Page

Blank Sudoku Template

Community Q&A

Question

How can I make money by making my own sudoku puzzles?

Community Answer

You could create a site with free sudokus and put ads on the site. You could also use ad.fly to let people download them for free -- ads show up while downloading, so you get a little money for each download. Or, simply make a large collection of them and sell as a printable PDF for a certain amount of money.
Question

How do I know if it is correct?

Community Answer

You can try it out and see if you can solve it correctly. If not, you will realize where there are errors and be able to correct them.
Question

After I create a full page Sudoku, how do I know how many numbers to remove?

Logan Eichfeld

Community Answer

This depends on how difficult you want your puzzle to be. If you want your puzzle to be easy, remove a small amount of numbers from the grid. If you want your puzzle to be intermediate, then remove a moderate amount of numbers from the grid. if you want your puzzle to be hard, remove a large amount of numbers from the grid.