How to Make Percentages Out of One-In Odds

You can express the odds of winning a raffle as a percentage.

The probability of an event occurring is between 1 and 0. A certain event has a probability of 1, or 100 percent, and an impossible event has a probability of 0, or 0 percent. You can express the chance of an event occurring in more than one way, such as 1-in-5 odds of winning a raffle or a 20 percent probability of winning a raffle. When probability is expressed as 1-in-x odds, 1 represents the number of favorable outcomes, and x represents the total number of possible outcomes. You can convert these odds to a percentage to compare with other similar probabilities.

Instructions

1. Determine the known 1-in-x odds of an event occurring that you want to convert to a percentage. For example, convert 1-in-2,000 odds to a percentage.

2. Divide the number of favorable outcomes by the total number of possible outcomes. In the example, divide the number of favorable outcomes of 1 by total number of possible outcomes of 2,000, which equals 0.0005.

3. Move the decimal two places to the right in your result and add a percent sign to convert to a percentage. In the example, convert 0.0005 to 0.05 percent. This means the probability of an event with 1 in 2,000 odds of occurring is 0.05 percent.

Tips & Warnings

• If your result is closer to 100 percent, the event has a likely chance of occurring. If it's closer to 0 percent, the event has a smaller chance of occurring.

References

• Cliffs Notes: Classic Theory
• Santa Monica College; Dr. Nestler's Math 21 Worksheet on Odds vs. Probability; Dr. Andrew Nestler