How Many Sudoku Puzzles are There?

If you’ve been solving Sudoku puzzles for a while, a question may have popped into your mind: How many possible Sudoku puzzles are there?

You can find plenty of Sudoku puzzle books with pages after pages filled with puzzles so it’s only natural to assume that some must be repeats or that we must be about to run out of Sudoku puzzles to solve. 

Well the short answer is no, we’re not only going to run out of Sudokus anytime soon.

How many possible Sudoku combinations are there?

There are 6,670,903,752,021,072,936,960 unique possible Sudoku grids. 

Or, in other words, there are six sextillion six hundred seventy quintillion nine hundred three quadrillion seven hundred fifty-two trillion twenty-one billion seventy-two million nine hundred thirty-six thousand nine hundred sixty possible unique grids.

That’s obviously an extremely large number. 

To put it in some perspective, if everyone (all 7.75 billion of us) completed ten Sudoku puzzles a day, every day of the year, it would still take over 235 million years to run out of sudoku puzzles with unique solutions. 

And to put 235 million years into perspective, that’s approximately how long ago dinosaurs first appeared on Earth. 

So no, we’re not going to run out of Sudoku puzzles any time soon. 

Of course, this only considers the typical 9×9 sudoku grid. It doesn’t take into account all the potential combinations of different sudoku variants of different sizes or formats. Such as Samurai sudoku.