Work out raffle winning chance instantly with clear inputs, formula shown and shareable results.
Draws are made without replacement, so the chance of missing every prize is C(total - your tickets, prizes) / C(total, prizes) and the answer is one minus that. Buying ten of five hundred tickets gives close to a 6% chance across three prizes rather than the 2% a single-draw calculation suggests.
Chance of no win
P(none) = C(total - yours, prizes) / C(total, prizes)
Expected wins
expected = prizes x your tickets / total tickets
P(none) = C(total - yours, prizes) / C(total, prizes). Draws are made without replacement, so the chance of missing every prize is C(total - your tickets, prizes) / C(total, prizes) and the answer is one minus that.
Buying ten of five hundred tickets gives close to a 6% chance across three prizes rather than the 2% a single-draw calculation suggests.
Enter tickets you hold, total tickets sold, number of prizes. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.