What does betting cost?

A bookmaker does not charge a fee. The charge is hidden inside the odds. This page turns it into dollars.

Where the number comes from

Add up the chances that the odds imply for every outcome of a market and you get more than 100%. The part over 100% is the bookmaker's margin. If the margin is 5%, then on average about $4.76 of every $100 staked stays with the bookmaker (5 divided by 105), whatever the result of any single bet.

The margins in the list above are averages over 88 days from the open Bet Better daily margin index, which measures 38 competitions every day. The method notes explain what is measured and what is estimated.

What this does not tell you

This is the average price of placing bets. It is not a forecast of what you will win or lose in a given week, which swings far more than the margin. It also assumes typical prices: some bookmakers charge more and some less, and the difference between them is often bigger than people expect.

More open data

A separate study looks at how well bookmaker odds matched real outcomes across 18,238 settled markets. All figures are free to reuse under CC BY 4.0 and are also served by a free API with no key.