Free tool
Lay stake & liability calculator.
Laying means playing bookmaker: you win small stakes and risk larger liabilities. This converts between the two — in either direction — so you always know what a lay actually risks.
Long odds bite. Laying at 10.0 means risking £9 to win £1 — nine losses' worth of profit gone in a single winner. The arithmetic here is simple; respecting it at the moment you click is the hard part, and no calculator does that for you.
The worked example
Lay £10 at 4.0: liability = £10 × 3 = £30. Selection loses — you keep the £10 stake, £9.50 after 5% commission. Selection wins — you pay £30. Now work backwards instead: you're only willing to risk £50 on a lay at 6.0. Stake = £50 ÷ 5 = £10. Sizing from liability, not stake, is how you stop one bad lay emptying a week of profits.
Straight answers
How is lay liability calculated?
Liability = lay stake × (lay odds − 1). Laying £10 at odds of 4.0 risks £30: if the selection wins you pay out £30, and if it loses you keep the £10 stake, minus commission.
What is the difference between lay stake and liability?
The lay stake is what you win if the selection loses (the backer's stake, which you keep). The liability is what you pay if it wins. At short odds they are close; at long odds the liability towers over the stake, which is why laying outsiders is riskier than it looks.
How much should I lay to risk a fixed amount?
Work backwards: lay stake = maximum liability ÷ (lay odds − 1). To risk no more than £50 at odds of 6.0, lay £10. Fixing liability rather than stake is how disciplined traders size lay bets.
Do I pay commission on a winning lay bet?
Yes — commission is charged on your net winnings in the market, whichever side you were on. Win £10 by laying and a 5% commission leaves £9.50. Rates vary by exchange and market, so check yours.
Every lay is a small win bought with a big risk. The skill is in the sizing.
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