Start with the total weight
An entry’s probability is its weight divided by the sum of all weights. With weights of 1, 2 and 3, the total is 6. The first entry gets 1/6, about 16.67%; the second gets 2/6, about 33.33%; the third gets 3/6, or 50%.
Enter your list, open “Edit probabilities” and set whole-number weights from 1 to 1,000. The percentages beside the entries show their current chances. Changing one weight changes every entry’s probability because the denominator changes too.
Ratios matter more than large numbers
Weights of 1:2:3 and 10:20:30 produce the same probabilities. Multiplying every weight by one number changes nothing. If one option should be twice as likely as another, weights of 1 and 2 are enough.
Increasing only the first weight from 1 to 2 produces 2:2:3. Its chance becomes 2/7, about 28.57%, rather than 33.33%. The total has also increased from 6 to 7. Keep this in mind when planning a particular proportion.
Repeated entries add weight too
Two entries named “Anna”, each with weight 1, and one “Boris” entry of weight 1 give each line a 1/3 chance. However, the label “Anna” has a combined chance of 2/3. For equal chances per person, keep one entry per person.
Distinguish people with the same name using aliases such as “Anna 1” and “Anna 2”. For multiple winners, Wheel and Names combines exactly matching labels and sums their weights. Labels with different capitalization remain separate.
A percentage describes the next pick
A 50% chance does not promise a win every other spin. Without removal, every new pick uses the same list; the previous result does not make an entry overdue.
Removing a winner reduces the total weight. If the entry of weight 3 is removed from 1:2:3, the remaining total is 3, giving chances of 1/3 and 2/3. A multiple-winner draw recalculates after each selected label. Decide whether you want repeatable selections or sampling without replacement before starting.
Put it into practice
Try weights on your wheelFor a step-by-step explanation of the random source, read the selection-method guide.
Read the guide