Implied Probability Calculator

Convert betting odds into the implied probability of an outcome. Enter odds in any format — American, decimal, or fractional.

What is Implied Probability?

Implied probability is the percentage chance of an outcome happening, as suggested by the betting odds. It tells you what the sportsbook thinks the likelihood of a result is, with their margin (vig) built in.

How to Find Value Bets

If you believe a fighter has a 60% chance of winning but the implied probability from the odds is only 50%, that's a value bet — the odds are offering better value than the true probability suggests. The bigger the gap between your estimated probability and the implied probability, the more value the bet offers.

Quick Reference

-200 implies a 66.7% chance — heavy favourite

-150 implies a 60.0% chance — moderate favourite

+100 implies a 50.0% chance — coin flip

+200 implies a 33.3% chance — underdog

+500 implies a 16.7% chance — big underdog

Diary of a Pro Gambler

Sports betting community with 10+ years of profitable results across UFC and Football. Live betting audio, daily tips, and data-driven tools.

18+ only. Gambling can be harmful. Content on this site is opinion and entertainment — not financial advice. Please gamble responsibly. Free, confidential help is available 24/7 on the National Gambling Helpline: 0808 8020 133.

© 2026 Diary of a Pro Gambler. All rights reserved.