Check your downside before you lay a selection. This calculator shows the exact liability at your odds and stake, plus the net profit if the selection loses.
Estimate risk on a single lay bet in seconds.
Compare liability vs. potential return after commission.
Confirm if the exposure fits your bankroll plan.
Tools are informational only, not betting advice, and do not guarantee profit.
See exactly how much you stand to lose when laying a selection.
Lay side · Betfair / exchange
This calculator is an educational tool for understanding lay bet exposure on betting exchanges. It does not provide betting advice, tips, or predictions.
Laying a selection means you win if it loses, but your liability can be many times your stake. Use this
calculator before you place a lay bet so you know exactly how much is at risk if the favourite or runner
you oppose goes on to win.
It is the amount you stand to lose if the selection you lay wins the event.
Does commission reduce liability?
No. Commission is only applied to profits on winning outcomes, so liability stays the same.
What odds format should I use?
Enter decimal odds. Most exchanges quote decimal by default, and the calculator assumes that format.
When to use a lay liability calculator
Every time you lay a selection on a betting exchange, you are taking the role of the bookmaker. If the selection wins, you must pay out the backer. Your lay liability is the maximum amount you could lose on that single trade, and it is always larger than the lay stake itself. Understanding this number before you commit to a trade is essential for responsible bankroll management.
A lay liability calculator is particularly useful when you are comparing two potential lay bets at different odds. A lay at 2.0 for £20 carries a liability of £20, but the same stake at 10.0 carries a liability of £180. Without checking, it is easy to underestimate how much capital the exchange will hold in your account while the bet is open.
Detailed worked example
Suppose you want to lay "Team A" at odds of 6.0 for a stake of £15 on Betfair with 2% commission.
Liability: (6.0 − 1) × £15 = £75.00. This is the amount deducted from your available balance while the bet is open.
If the selection loses (you win): You keep the backer's stake minus commission: £15 × (1 − 0.02) = £14.70 profit.
If the selection wins (you lose): You pay out the full liability of £75.00.
The risk-to-reward ratio here is 75 / 14.70 = roughly 5.1 to 1. This means you need the selection to lose more than five times out of six just to break even over time. This kind of calculation helps you decide whether the lay price offers genuine value based on your assessment of the selection's true chance of winning.
Common mistakes with lay betting
Confusing stake and liability: The lay stake is what you stand to win (before commission). The liability is what you stand to lose. They are not the same, and at higher odds the difference grows rapidly.
Forgetting commission on winnings: Commission only applies when your lay bet wins (the selection loses). It does not reduce your liability if you lose.
Laying at very high odds without checking liability: Laying at 50.0 for just £2 creates a liability of £98. Always check before confirming.
Not accounting for in-play odds movement: If you plan to trade out in-play, your initial liability still applies until you place the offsetting bet.
