Calcudoku is a game combining arithmetic and grid-based logic similar to Sudoku.

Einstein's Riddle

Einstein said that only 2% of the world could solve this problem. Can you do it?

Greek Logic

Fill the grid using the Greek letters.


Choose nine unique number using one simple rule.

Logic Equations

Using logic and basic algebra, solve the equations.

Logic Grid Puzzles

Complete the grid by using logic and the given clues of each problem.

Self-Referential Quiz

Quizzes where you only need logic to solve them.


Play the classic japanese logic game.

Zebra Puzzles

Use logic deductions to solve problems that are similar to the Einstein's Riddle.