Collatz Conjecture Calculator

Discover the amazing Collatz sequence with our Collatz conjecture calculator. Uncover patterns in this intriguing mathematical phenomenon. Try it now!

Clear
Steps to reach 1111total stopping time
Highest value reached9,232
Peak multiple of the start×341.926
Terms shown60 of 112

The trajectory

27 → 82 → 41 → 124 → 62 → 31 → 94 → 47 → 142 → 71 → 214 → 107 → 322 → 161 → 484 → 242 → 121 → 364 → 182 → 91 → 274 → 137 → 412 → 206 → 103 → 310 → 155 → 466 → 233 → 700 → 350 → 175 → 526 → 263 → 790 → 395 → 1186 → 593 → 1780 → 890 → 445 → 1336 → 668 → 334 → 167 → 502 → 251 → 754 → 377 → 1132 → 566 → 283 → 850 → 425 → 1276 → 638 → 319 → 958 → 479 → 1438 → …

The formula

even → n⁄2, odd → 3n + 1, repeat until 1

An open problem

The Collatz conjecture says every starting number eventually reaches 1. It has been checked far beyond 10²⁰ without a counterexample, and it remains unproved — Erdős remarked that mathematics is not yet ready for such problems.

Starting at 27 is the classic demonstration: it takes 111 steps and climbs as high as 9,232 before collapsing.