Weighted Wheel Probability: Set and Check Your Odds
Learn how weighted wheel odds work with a 3:1 example. Set entry weights, understand no-repeat rounds and avoid misleading conclusions from spin history.
A weight is an entry’s share of the eligible wheel. Give every entry weight 1 for equal odds, or assign larger weights when some choices should be more likely. The formula is the entry’s weight divided by the total eligible weight.
Set up a weighted wheel →A 3:1 example: 75% versus 25%
Suppose Pizza has weight 3 and Salad has weight 1. The total is 4, so Pizza has 3 ÷ 4 = 75% chance and Salad has 1 ÷ 4 = 25% chance on each random-mode spin. A larger weight also draws a larger segment.
These are probabilities, not a schedule. Four spins do not guarantee exactly three Pizza results. A short run can repeat either choice several times.
| Choice | Weight | Chance |
|---|---|---|
| Pizza | 3 | 75% |
| Salad | 1 | 25% |
| Total | 4 | 100% |
Set weights on your wheel
Use one entry for each distinct outcome. You do not need to duplicate the same label to increase its chance; a weight makes the intended odds easier to maintain.
- Open Weights & colors in the Entries panel.
- Enter a whole-number weight from 1 to 1,000,000 for each choice.
- Leave the field to save the change.
- Keep all entries at weight 1 to return to equal odds.
Understand how no-repeat rounds change the odds
Only eligible entries contribute to the next draw. If Pizza has already won in No Repeats, it is excluded for the rest of that round, even though its saved weight is still 3. If Salad is the only remaining choice, its next-draw chance is 100%.
Changing a weight changes the chance of being picked next; it does not clear the round’s used names. In a full Fair Round each eligible entry still gets one turn, so weighting affects the order rather than how many turns it gets.
How a weighted result is selected
The application asks the browser’s crypto.getRandomValues source for an integer. Rejection sampling avoids bias when mapping that integer into the eligible total weight. Each entry owns a consecutive range of tickets equal to its weight.
The selected result is saved before animation begins. Duration, sound, deceleration and the manual stop button change the presentation, not which ticket wins.
Interpret your results carefully
Keep the entry list, enabled states and weights unchanged if you want to compare observed frequencies with a fixed expected distribution. Mixing earlier spins with a new configuration does not test the same probability model.
The current results page compares history with current settings, so its approximate fairness label is not reliable after entries or weights change. Export the history for your own analysis. No local log or statistical result is an independently verifiable proof of a draw.
Common questions
Does a bigger wheel segment have a better chance?
Yes, when you increase its entry weight. Segment area and selection probability use the same weights. Colors and the order of entries do not change odds.
Can I use decimal weights?
Weights must be positive whole numbers. Use an equivalent ratio: for example, 15 and 10 represent the same relative odds as 1.5 and 1.
Can the same choice win twice?
In Random mode, yes. Switch to No Repeats or Fair Round to exclude each selected entry until a new round starts.
Explore the selection methodology and probability simulator.