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Tower of Hanoi with 6 Disks

The shortest solution is 63 moves. Play them on the board, or read every one in the list under it.

Optimal solution

63moves2⁶ − 1

First move
Disk 1, A → B
At one move a second
1 minute
Difficulty
Medium

6 disks on tower A. 63 moves to go.Step 0 of 63

Every move of the 6-disk solution
MoveDiskFromTo
11AB
22AC
31BC
43AB
51CA
62CB
71AB
84AC
91BC
102BA
111CA
123BC
131AB
142AC
151BC
165AB
171CA
182CB
191AB
203CA
211BC
222BA
231CA
244CB
251AB
262AC
271BC
283AB
291CA
302CB
311AB
326AC
331BC
342BA
351CA
363BC
371AB
382AC
391BC
404BA
411CA
422CB
431AB
443CA
451BC
462BA
471CA
485BC
491AB
502AC
511BC
523AB
531CA
542CB
551AB
564AC
571BC
582BA
591CA
603BC
611AB
622AC
631BC
On this page
  1. The solution
  2. The shape of the solution
  3. Which disk moves when
  4. The smallest disk's circuit
  5. About the 6-disk puzzle
  6. Other sizes
  7. Frequently asked questions

The shape of the solution

There are never 63 separate moves to remember — only three stages:

  1. Moves 1 to 31: build a tower of 5 disks on B.
  2. Move 32: disk 6 crosses to C — the only time it moves.
  3. Moves 33 to 63: rebuild the 5-disk tower on top of it.

Stages 1 and 3 are each the 5-disk solution, with two towers' names swapped.

Which disk moves when

Disk 1 makes half of all the moves — 32 of them, on every odd-numbered move. Each larger disk moves half as often as the one above it, which is the binary counter hiding inside the puzzle: the disk that moves is one more than the number of times you can halve the move number and still get a whole number. Move 6 halves once, to 3, so move 6 is disk 2. There is more on that in Tower of Hanoi and binary.

DiskMovesFirst moves onThen every
132move 12 moves
216move 24 moves
38move 48 moves
44move 816 moves
52move 1632 moves
61move 32

The smallest disk's circuit

With 6 disks — an even number — disk 1 travels A → B → C → A for the whole game, never reversing. Every move in between is the only legal move that leaves disk 1 alone. Those two rules alone reproduce the list above move for move; the iterative solution explains why, and strategies turns it into something to play by.

About the 6-disk puzzle

Sixty-three moves is where a game stops being something you finish in one breath and starts needing checkpoints. Halves are too coarse to catch a slip in time, so hold six disks in your head by quarters instead:

  • After move 15: disks 1 to 4 are on C.
  • After move 31: disks 1 to 5 are on B, and disk 6 is alone on A. Move 32 carries it to C.
  • After move 47: disks 1 to 4 are alone on A, disk 5 is on B and disk 6 is on C. Move 48 puts disk 5 on disk 6.
  • Moves 49 to 63: disks 1 to 4 come home.

Each checkpoint is a finished four- or five-disk tower, which is easy to see at a glance — and if the board does not match, you have found your mistake within fifteen moves of making it.

Six is even, so the smallest disk starts toward B. It makes thirty-two of the sixty-three moves, and every one of them is forced. Sixty-three is 3 × 3 × 7 — the first move count that is divisible by both earlier primes, seven and three.

Other sizes

Frequently asked questions

How many moves does it take to solve Tower of Hanoi with 6 disks?

63 moves is the minimum: 2⁶ − 1 = 63. No solution with fewer moves exists, and any solution with more has wasted some.

What is the first move in 6-disk Tower of Hanoi?

Move disk 1, the smallest, from tower A to tower B. With an even number of disks the smallest disk travels A → B → C → A for the whole game, so its first stop is B. Sending it to C first still lets you finish, but it costs one extra move.

How long does 6-disk Tower of Hanoi take to solve?

A perfect game is 63 moves, which at one move a second is 1 minute and at three moves a second — about as fast as anyone plays by hand — 21 seconds.

How can I check I am on track in a 6-disk game?

Look at the board after moves 15, 31 and 47. After move 15, disks 1 to 4 should be stacked on C. After move 31, disks 1 to 5 should be on B, with disk 6 alone on A. After move 47, disks 1 to 4 should be on A, with disk 6 on C and disk 5 on B. If the board matches at each of those moves, you are still on the shortest path.