Spin The Wheel
Free Spin the Wheel. Free online tool with accurate results using verified formulas. Includes worked examples, FAQ, and instant calculations.
Formula
P(segment) = 1 / number of segments
Each segment has equal probability of being selected. With n segments, each has a 1/n (or 100/n percent) chance of being chosen.
Worked Examples
Example 1: Equal Probability Calculation
Problem: A wheel has 8 equal segments. What's the probability of landing on any specific segment?
Solution: Each segment has equal probability:\n\nP(specific segment) = 1/n = 1/8 = 0.125 = 12.5%\n\nAll 8 segments sum to 100%:\n8 × 12.5% = 100% ✓
Result: 12.5% chance for each segment
Example 2: Weighted Probability (Multiple Entries)
Problem: You add 'Gym' 3 times and 'Rest' 1 time. What are the probabilities?
Solution: Total entries: 3 + 1 = 4\n\nP(Gym) = 3/4 = 75%\nP(Rest) = 1/4 = 25%\n\nBy adding 'Gym' multiple times, it has 3x the probability of 'Rest'.
Result: Gym: 75%, Rest: 25%
Example 3: Multiple Spins
Problem: What's the probability of landing on 'Pizza' twice in a row with 5 options?
Solution: Each spin is independent.\n\nP(Pizza) = 1/5 = 0.2 per spin\n\nP(Pizza twice) = P(Pizza) × P(Pizza)\n= 0.2 × 0.2 = 0.04 = 4%\n\nThe more spins required, the lower the probability.
Result: 4% chance of Pizza twice in a row
Frequently Asked Questions
How does the spin the wheel work?
The wheel uses random number generation to determine the rotation amount. It spins 5-10 full rotations plus a random angle, then calculates which segment is at the top when it stops. Each segment has an equal probability of being selected based on its size (equal for all entries).
Is the wheel truly random?
Yes! The wheel uses JavaScript's Math.random() which provides pseudo-random numbers. Each segment has exactly equal probability (1/n where n is the number of items). There's no weighting or bias - every option has the same chance of being selected.
How many items can I add to the wheel?
This wheel supports 2-12 items. Two items is the minimum for a meaningful choice. Twelve is the maximum to keep segments visible and readable. For more complex decisions with many options, consider using a random picker list instead.
What are good uses for a spin wheel?
Popular uses include: Deciding where to eat, picking what movie to watch, classroom random student selection, game show style prizes, team member selection, chore assignment, restaurant menu decisions, gift exchange picking, and breaking decision deadlock in groups.
What's the math behind wheel probability?
For a wheel with n equal segments: P(any specific segment) = 1/n. With 6 items, each has 16.67% chance. With 4 items, each has 25% chance. The formula for k specific items from n segments over multiple spins follows binomial distribution.
Can I save my wheel configurations?
Currently, wheel configurations aren't saved between sessions. For repeated use, you can bookmark the page and re-enter items. Future versions may include save functionality. You can also screenshot your configuration to recreate it.