Wheel Probability Calculator

About this calculator

For a wheel divided into equal segments — a prize wheel, roulette-style spinner, or raffle wheel — the probability of landing on any single segment on one spin is simply 1 divided by the number of segments. But predicting outcomes over many spins requires binomial probability: the expected number of hits equals the per-spin probability times the number of spins, while the chance of landing on a target segment at least once uses the complement rule, 1 minus the probability of missing it every single time.

This calculator applies both formulas to a wheel with a given number of segments and spins, returning the per-spin odds, expected hits, and at-least-one-hit probability. It's useful for game designers balancing prize-wheel odds, streamers and promoters running wheel-spin giveaways, and students working through basic probability and binomial distribution problems who want a concrete, spin-based example to check their own calculations against.