Skip to main content.

Statistics on Difficulty of Sudokus

There is now reliable, objective way to measure the difficulty of a given Sudoku. Therefore these statistics compiled from how fast or slow humans solved the Sudokus on the one hand, and how many people solved a given Sudoku on the other hand.

Average Solving Time

All times are given in Seconds.

Overall Statistics

Average602
Std. Deviate99
Minimum374
Maximum1894

Easiest and Hardest Sudokus

The Sudokus that were solved fastest/slowest on average.

EasiestHardest
NoMean Time [s]Sudoku Mean Time [s]Sudoku
1 374 2017-06-09 1894 2011-01-22
2 380 2013-05-01 1380 2006-10-14
3 382 2013-05-02 1292 2013-07-09
4 382 2015-06-29 1117 2011-06-30
5 388 2017-04-09 1098 2010-04-21
6 392 2015-06-28 1033 2008-10-29
7 395 2010-08-04 1026 2009-11-18
8 396 2011-06-12 1016 2010-12-25
9 400 2011-03-25 986 2012-02-04
10 400 2011-07-31 978 2013-03-06
11 403 2013-05-03 946 2010-02-06
12 405 2009-12-03 934 2013-08-21
13 405 2018-01-17 925 2012-02-14
14 407 2017-04-11 922 2007-09-07
15 410 2009-11-15 919 2013-02-04

Number of People Who Solve a Sudoku

Most Difficult Sudokus

These Sudokus have been solved lest often:

NumberSudoku
102018-01-22
492017-04-10
492018-01-02
492018-01-14
492017-11-07
522017-09-19
522016-10-10
532017-10-07
542017-07-28
542017-11-13
542017-09-27
552015-07-16
552017-06-14
552017-09-26
552016-08-28