How is the single-draw probability calculated?

For one prize, probability = your tickets / total tickets. For multiple prizes drawn sequentially without replacement, the at-least-one-win probability uses the complement method: 1 minus the probability of winning zero prizes across all draws.

What is "at least one win" probability?

It is the chance that you win at least one prize when multiple prizes are awarded. It equals 1 minus the hypergeometric probability of you winning exactly zero prizes.

Does it matter if prizes are drawn with or without replacement?

This calculator assumes without replacement (the most common raffle format): once a ticket wins a prize it is removed from the pool. If your raffle uses replacement, the at-least-one formula changes slightly.

Can I hold more tickets than the total?

No. Your ticket count must be less than or equal to total tickets sold, and total tickets must be greater than zero.

How many prizes can I enter?

Prizes must be at least 1 and no more than the total number of tickets (you cannot award more prizes than tickets exist).

Raffle Win Probability Calculator

Name: Raffle Win Probability Calculator
Availability: InStock
Author: Nham Vu

Enter your tickets, total tickets, and prize count to instantly see your exact odds of winning.

Raffle Details

Your Tickets

How many tickets you purchased

Total Tickets Sold

All tickets in the raffle pool

Number of Prizes

Total prizes being awarded

Your Odds

Fill in the details and click Calculate Odds.

How Ticket Count Affects Your Odds

At-least-one-win probability for different ticket counts (total tickets and prizes held constant).

Your Tickets	At-Least-One-Win	1 in N

Summary

Enter your tickets, total tickets, and prize count to instantly see your exact odds of winning.

How it works

Enter your ticket count, total tickets, and number of prizes.
The single-draw probability is your tickets divided by total tickets.
The at-least-one-win probability uses the hypergeometric complement formula.
Results are shown as a percentage, a ratio, and a 1-in-N fraction.

Use cases

Decide how many raffle tickets to buy to hit a target win probability.
Compare your odds across different raffles before purchasing.
Understand the impact of prize count on your overall winning chances.
Calculate office pool odds when splitting a block of tickets.
Evaluate charity raffle value against ticket price.
Teach probability concepts with a relatable real-world example.

Frequently Asked Questions

Last updated: 2026-07-24 · Reviewed by Nham Vu