Calculate liability, profit, and stakes for lay bets on betting exchanges
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Enter your lay bet parameters
The odds you're laying at
Your lay bet breakdown
You pay the backer's winnings (liability)
You keep the backer's stake (minus commission)
Amount Required
$200
Implied Prob
33.3%
Lose Prob
66.7%
Risk/Reward
2.11:1
Common lay bet scenarios
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Understanding exchange lay bets
Back = Betting FOR something to win
Lay = Betting AGAINST something to win
Matched betting, trading, hedging positions, or simply when you think something won't win.
TL;DR summary
A lay bet is betting AGAINST an outcome - you win if the selection loses. On a betting exchange, laying at 3.00 odds for $100 stake means: Liability = ($100 × (3.00-1)) = $200 you could lose if selection wins. Profit = $100 × (1-5% commission) = $95 you win if selection loses. Always know your liability before placing lay bets!
Important things to know
Common questions about lay betting
A lay bet is the opposite of a traditional "back" bet. Instead of betting that something will win, you're betting that it won't win. You're essentially acting as the bookmaker, accepting someone else's bet. If the selection loses, you win their stake (minus commission). If it wins, you pay out their winnings.
Liability is the amount you stand to lose if the selection wins. It's calculated as: Liability = Stake × (Odds - 1). For example, if someone backs a horse at 4.00 for $50, your liability is $50 × 3 = $150. This amount is held by the exchange until the event settles.
Commission is charged on your net winnings only (when you win). Standard Betfair commission is 5%, but can be as low as 2% for frequent traders. If you lay $100 at 3.00 odds and win, your gross profit is $100, but after 5% commission, you receive $95.
Lay betting is useful when: (1) You think something won't win but can't identify the winner, (2) You want to trade positions by laying after backing, (3) You're matched betting to extract value from bookmaker offers, (4) You believe the odds are too short (selection is overrated).
In a dead heat, the odds are adjusted. Your liability is reduced proportionally. For example, in a 2-way dead heat, you'd pay out half the normal amount. The exchange handles this automatically when settling bets.
No. Your maximum loss is always your liability, which is held by the exchange when you place the bet. You cannot lose more than this amount. This is why exchanges require you to have sufficient funds to cover liability before accepting your lay bet.