Lay Bet Calculator

How Lay Betting Works

Laying a bet means acting as the bookmaker. Instead of backing a selection to win, you are taking someone else's bet - effectively betting that the selection will NOT win. If the selection loses, you keep their stake. If it wins, you pay out their winnings from your liability.

Matched Betting Basics

Matched betting uses lay bets to cancel out the risk of a back bet. When a bookmaker offers a free bet or bonus, you back the selection at the bookmaker and lay it at the exchange. The two bets largely cancel each other out, leaving you with a profit from the free bet regardless of the outcome.

Understanding Liability

Liability is the maximum amount you would lose if the selection wins. It is calculated as your lay stake multiplied by (lay odds minus 1). For a lay of 10 at odds of 4.00, liability = 10 x 3 = 30. This is held by the exchange until the event settles.

Exchange Commission

Betfair charges a commission on winning lay bets, typically 2% for new users. This reduces your effective profit. Always account for commission when calculating whether a matched bet is worthwhile. Most matched betting calculators (including this one) factor commission into the lay stake calculation.

For more on exchange betting and lay markets, see our glossary entry for lay bet and the betting markets guide.