What does “what the operator keeps from €1,000 staked” mean?

It is the average expected loss if the margin is spread evenly across the outcomes: 1,000 × (1 − 1 ÷ total of the probabilities). A 5% margin represents about €48 per €1,000 staked, a 1.5% margin about €15.

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Free tool

Bookmaker margin calculator

Enter a match's odds at one or two operators. The calculator gives the margin taken, the fair odds and what each keeps, on average, from €1,000 staked.

Operator A

1 N 2

Operator B (optional)

1 N 2

Leave “N” empty for a two-way bet (tennis, basketball, over/under goals). Clear operator B to calculate just one.

	A	B
Margin
Kept from €1,000
Fair odds 1
Fair odds N
Fair odds 2

How to read the result

The margin is the share the operator takes on the match, whatever the result. Below 4%, the price is tight; above 7%, it is expensive.
Kept from €1,000 is the average expected loss if you staked €1,000 on this market at the price offered. It is the most concrete way to compare two operators.
The fair odds are what an operator taking nothing would post. The gap between offered and fair odds is what you pay on every bet.

The calculation in detail, with a step-by-step example, is in our guide understanding bookmaker margins. To see each operator's margin on upcoming matches without typing anything, open the margin comparison.

Frequently asked questions

How do you calculate a bookmaker's margin?

Add up the inverse of each of the match's odds, then subtract 1. With 1.90, 3.50 and 4.20: 0.526 + 0.286 + 0.238 = 1.050, a margin of 5.0%.

Why compare two operators rather than one?

Because a margin only means something relative to another. In the example above, going from a 5.0% to a 1.5% margin cuts what the operator keeps from €48 to €15 per €1,000 staked, without a single prediction changing.

Does this calculator work for tennis or basketball?

Yes. Leave the draw price empty: the calculation then uses two outcomes.

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