Free Tools

Betting Calculators

Size every bet, evaluate every price, convert every format. The same maths sharps run — built into clean, mobile-friendly tools.

Odds Converter

Instantly convert between American, decimal, and fractional odds formats. Enter a value in any field to see all conversions.

Common Odds Reference

AmericanDecimalFractionalProbability
-5001.2001/583.3%
-2001.5001/266.7%
-1501.6672/360.0%
-1101.90910/1152.4%
+1002.0001/150.0%
+1502.5003/240.0%
+2003.0002/133.3%
+3004.0003/125.0%
+5006.0005/116.7%

Understanding Odds Formats

Different regions of the world use different odds formats. American odds (+150, -200) are standard in the US. Decimal odds (2.50, 1.67) are used in Europe, Australia, and Canada. Fractional odds (3/2, 2/1) are traditional in the UK and Ireland. They all represent the same thing — just expressed differently.

Reading American Odds

Negative odds (e.g., -150) tell you how much you need to stake to win $100. So -150 means stake $150 to win $100 profit. Positive odds (e.g., +200) tell you how much profit you'd make on a $100 stake. So +200 means $100 wins you $200 profit.

Reading Decimal Odds

Decimal odds show the total return per unit staked (including your original stake). Odds of 2.50 mean $1 returns $2.50 total ($1.50 profit + $1 stake back). To calculate profit: multiply your stake by the decimal odds and subtract your stake.

Reading Fractional Odds

Fractional odds show profit relative to stake. Odds of 3/1 mean for every $1 staked, you win $3 profit. Odds of 1/2 mean for every $2 staked, you win $1 profit. The left number is profit, the right number is the stake required.

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.