How betting odds work
Decimal, fractional and implied probability — explained in five minutes.
Updated 4 Oct 2026
Odds tell you two things: how much you win, and how likely the bookmaker thinks an outcome is.
Decimal odds
Decimal odds show your total return per £1 staked, including your stake. A £10 bet at 2.50 returns £25 — £15 profit plus your £10 back.
Fractional odds
Fractional odds show profit relative to stake. 6/4 means £6 profit for every £4 staked — the same as 2.50 in decimal. To convert: divide the fraction and add 1.
Implied probability
Divide 1 by the decimal odds: 1 ÷ 2.50 = 0.40, so the price implies a 40% chance. Add up the implied probabilities for every outcome in a market and you'll get more than 100% — the excess is the bookmaker's margin (the "overround").
Why it matters
Every bet is a bet on price. If you think an outcome is more likely than the odds imply, it's a value bet. Every tip on this site records the exact price available when it was posted, so results reflect odds you could actually have taken.