A price that is higher than the odds your own probability estimate implies. If you think an outcome has a 50% chance, fair odds are 2.00, so a price of 2.20 is above fair odds. It does not mean the bet will win.

How is the edge calculated?

Edge = probability × decimal odds − 1. With a 50% probability and odds of 2.20, the edge is 0.5 × 2.20 − 1 = +10%. A negative figure means the price is below fair odds.

Where does the probability come from?

Choose an upcoming match and market to use our Dixon-Coles model probability, which is published before kick-off and graded publicly afterwards. Or switch to 'Use your own probability' and enter any percentage.

Does a positive edge guarantee profit?

No. A positive edge only means the price is higher than our model's estimate. Models can be wrong, and even correct probabilities lose often: a 50% chance loses half the time.

Do you recommend stake sizes?

No. The calculator compares prices with probabilities only. We do not suggest stakes or staking plans.

Value Bet Calculator: Find the Edge Against Bookmaker Odds

With a probability of 50.0% for an outcome, fair odds are 2.00. A bookmaker price of 2.20 implies 45.5%, so the edge is 10.0%: price is above our fair odds by 10.0%.

New to this? Read: What is a value bet? · How accurate are football predictions?

How to use the value bet calculator

Pick an upcoming match from the search box and choose a market: home win, draw, away win, or Over/Under 1.5, 2.5 or 3.5 goals. Our model probability fills in automatically. Then type the bookmaker's price in any format, such as 2.20, 6/5 or +120. The calculator shows our probability, our fair odds, the bookmaker's implied probability and the difference between them as an edge. If you have your own estimate, switch to "Use your own probability" and skip the match search.

Every match page has a link that opens this calculator with the fixture already chosen. The address bar keeps your inputs, so you can share a comparison.

The formulas

Fair odds = 1 ÷ probability. 50% gives 2.00; 40% gives 2.50.
Bookmaker implied probability = 1 ÷ decimal odds.
Edge = probability × decimal odds − 1, shown as a percentage.

Worked example 1: your own estimate

You think a team has a 50% chance of winning and the bookmaker offers 2.20. Fair odds for 50% are 2.00. The bookmaker's price implies 45.5%. Edge = 0.50 × 2.20 − 1 = +10%, so the price is above our fair odds by 10%. If the bookmaker offered 1.80 instead, the edge would be 0.50 × 1.80 − 1 = −10%: the price is below fair odds by 10%.

Worked example 2: Over 2.5 goals

Our model gives Over 2.5 goals a 58% chance in a match, so our fair odds are 1.72. A bookmaker offers 10/11 (1.91), which implies 52.4%. Edge = 0.58 × 1.91 − 1 = +10.7%. That only tells you the price is higher than our estimate. Over many such matches a calibrated 58% still fails 42 times in 100, and a single result says almost nothing.

How to read the result

A positive edge means our probability is higher than the bookmaker's implied probability. A negative edge means the reverse. Our model does not know about injuries, team news or motivation, so a large edge is often a sign that the bookmaker knows something the model does not. Check how our numbers have performed on the accuracy page, including our comparison with bookmaker closing prices, before trusting any edge.

Common mistakes

Treating edge as a forecast of profit on one bet. It is a comparison of two estimates, nothing more.
Comparing with a stale price. Odds move; use the current price.
Ignoring the margin. A bookmaker's implied probability includes their margin, which our implied probability calculator can strip out.

Browse today's home win, away win and Over 2.5 goals predictions, convert prices with the odds converter, or read the methodology.

Value bet Calculator: Compare Bookmaker odds with our Probabilities