Work out winner selector instantly with clear inputs, formula shown and shareable results.
Winners are drawn without replacement, so the chance of missing every prize is C(total - your entries, winners) / C(total, winners) and the answer is one minus that. Multiple prizes raise your odds more than a single-draw calculation suggests, because each unsuccessful draw removes a rival entry from the pool.
Chance of no win
P(none) = C(total - yours, winners) / C(total, winners)
Chance of winning
P(win) = 1 - P(none)
P(none) = C(total - yours, winners) / C(total, winners). Winners are drawn without replacement, so the chance of missing every prize is C(total - your entries, winners) / C(total, winners) and the answer is one minus that.
Multiple prizes raise your odds more than a single-draw calculation suggests, because each unsuccessful draw removes a rival entry from the pool.
Enter total entries, your entries, number of winners. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.