The Bookmaker's Margin: What You Pay on Every Bet, Measured on 600+ Matches
Every price hides a fee. We measured it at Toto, Unibet, Polymarket and Overtime over 600+ football matches: from about 2% to 8%, depending on where and what you bet.
Last reviewed November 3, 2026
Key takeaways
- >The margin is how far a market's implied probabilities add up above 100%
- >Median 1X2 margin before kickoff: Toto 5.9%, Overtime 4.0%, Unibet 3.1%, Polymarket 2.0% (506–634 matches each)
- >Over/under 2.5 and both-teams-to-score cost more: 6–8% at Toto and Unibet
- >Over €1,000 of bets that is an expected cost of roughly €56 at 5.9% against €20 at 2.0%
- >Taking the best price per outcome across books cut the median 1X2 margin to 2.7% (Toto + Unibet) and about 1% (all four)
Every bookmaker price contains a small fee you never see on the bet slip. It is called the margin (also the overround or the vig), and it is the reason a bookmaker can lose on individual matches and still make money over a season. We measured it at four venues over more than 600 football matches. The short version: depending on where you bet, the same bet costs you between roughly 2% and 8%, and that difference adds up faster than almost anything else in betting.
What the margin is
Convert every outcome's odds to an implied probability (1 ÷ decimal odds) and add them up. In a world without a bookmaker, the outcomes of a match would add up to exactly 100%: one of them is certain to happen. A bookmaker shortens every price a little, so the total comes out above 100%. The part above 100% is the margin.
Margin = (1 / odds₁ + 1 / odds₂ + … ) − 1
One match, four margins
Aston Villa vs Fulham, Premier League, 31 October 2026. These were the last prices we recorded at each venue before kickoff:
Venue | Villa | Draw | Fulham | Total implied | Margin |
|---|---|---|---|---|---|
Toto | 1.99 | 3.55 | 3.60 | 106.2% | 6.2% |
Unibet | 1.91 | 3.95 | 4.10 | 102.1% | 2.1% |
Polymarket | 2.04 | 3.85 | 3.85 | 101.0% | 1.0% |
Overtime | 2.00 | 3.67 | 3.74 | 104.0% | 4.0% |
The match finished 1-1. €10 on the draw paid €25.50 profit at Toto and €29.50 at Unibet: €4.00 more for the same correct prediction, purely because of the price.
Notice that the books do not just charge different margins, they also disagree about the match. Unibet rated Villa as the bigger favourite (1.91, against Toto's 1.99), yet paid more on the draw and on Fulham. Taking the margin out (next section) separates the opinion from the fee.
Taking the margin out: the "fair" price
To see what a book really thinks, divide each implied probability by the total. For Villa at Toto: 50.3% / 106.2% = 47.3%. That number is the book's own estimate without its fee, and the fair odds are 1 / 0.473 = 2.11, against the 1.99 actually offered. Unibet's estimate, the same way, was 52.4% / 102.1% = 51.3%: a genuinely different opinion of the same match.
This simple method spreads the margin evenly over the outcomes. Bookmakers do not always load every outcome equally, so treat the result as a good estimate, not an exact one.
What we measured: 600+ matches, four venues
For every finished match we have prices for, we took each venue's last price before kickoff for every outcome, and calculated the margin. These are the medians (the typical match; half were higher, half lower):
Venue | 1X2 (home/draw/away) | Over/Under 2.5 goals | Both teams to score |
|---|---|---|---|
Toto | 5.9% (628 matches) | 6.0% (628) | 8.0% (627) |
Unibet | 3.1% (634) | 6.3% (634) | 7.5% (634) |
Overtime | 4.0% (610) | 4.1% (470) | not in our data |
Polymarket | 2.0% (506) | not in our data | not in our data |
Matches: Eredivisie, Premier League, La Liga, Bundesliga, Serie A, Ligue 1, and the Champions League, Europa League and Conference League, played between August and early November 2026.
Four things stand out:
- Toto is consistently the most expensive on the main market, at around 6% on 1X2 in almost every league. The exception is the Eredivisie, where its median was 3.1%, in line with Unibet's 2.9% there.
- Unibet varies by league. Its 1X2 margin was 2.4% in the Premier League and 2.6% in the Champions League, but 5.2% in Ligue 1 and 5.7% in the Conference League.
- The side markets cost more. Over/under and both-teams-to-score carried 6–8% at Toto and Unibet, roughly double Unibet's 1X2 margin.
- Polymarket was the cheapest by a distance, around 2% on 1X2. It has no bookmaker: the price is set by other users, and what you pay is the gap between the best buy and sell prices in its order book. (Our Polymarket prices are the price you could actually buy at.)
What the margin costs you
A rough rule of thumb: if a book's prices are right apart from the margin, every euro you stake comes back as about 1 / (1 + margin) in the long run. At a 5.9% margin that is about €0.944 per euro; at 2.0% it is €0.980.
Over €1,000 of bets, that is an expected cost of roughly €56 at a 5.9% margin, €30 at 3.1%, and €20 at 2.0%. The predictions are identical; only the venue changed. It is also why a betting strategy that looks slightly profitable at one book can be a loser at another.
Shopping for the best price
You do not have to accept one book's margin. If you take the best price for each outcome from several venues, the combined margin drops sharply. Over the same matches:
- Best of Toto and Unibet: median margin 2.7% (624 matches).
- Best of all four venues: median margin about 1.0% (473 matches).
One caution with that last number: the four venues' prices were recorded at slightly different times, so a combined book is a little more favourable on paper than it would have been to bet at a single moment. When the best prices across venues add up to less than 100%, you are looking at a possible surebet, which has its own explainer.
Frequently asked questions
Does a lower margin mean I am more likely to win?
It means you pay less for every bet. Whether a bet wins depends on the match. Over hundreds of bets, though, the margin is the one cost you can control in advance.
Why are over/under and both-teams-to-score more expensive?
We measured them as more expensive at both Toto and Unibet, but we do not know either book's pricing model, so we will not guess why. The practical point stands: the side markets cost more.
Can a margin be negative?
At a single bookmaker, practically never. Across different venues, the best prices can add up to under 100%: that is what a surebet is.
Is the margin the same as a commission?
It does the same job, but it is hidden in the price instead of charged on top. That is exactly why it is worth calculating.
How we measured this: for every finished match in Edge Terminal's odds history, the last price recorded before kickoff for each outcome at each venue. Because prices are collected by hand once a day, that is usually the morning of the match, sometimes the day before. A match counts for a venue only when every outcome was priced there; implied totals below 98% or above 125% were excluded as broken data (6 market-venue cases). Polymarket prices are 1 ÷ the best ask. Margins are medians. Snapshot taken 3 November 2026.