Reviewed by TipsterCheck Editorial TeamLast checked 26 October 2026MethodologyCorrections
Free tool
Lay Bet Calculator
What is liability on a lay bet?
Liability
£40.00
Win if it loses
£9.50
Lose if it wins
−£40.00
Cover a back bet
Lay stake needed
£8.08
Liability
£32.32
Result either way
−£2.32
How it works
- Liability (what you can lose) = lay stake × (lay odds − 1).
- If the selection loses, profit = lay stake × (1 − commission rate). If it wins, you lose the liability.
- To balance a back bet: lay stake = back stake × back odds ÷ (lay odds − commission), which gives an equal result either way.
Worked examples
Lay £10 at 5.0, 5% commission
Liability £40. You win £9.50 if it loses, or lose £40 if it wins.
Lay £50 at 1.5, 2% commission
Liability £25. You win £49 if it loses and lose £25 if it wins.
Cover £10 back at 4.0 with a lay at 4.2 (5%)
Lay stake £9.64, liability £30.84: about −£0.84 either way, a typical qualifying-bet cost.
Frequently asked questions
Further reading
Betting exchanges hub
Laying, commission and Betfair SP explained.
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Value betting, dutching, hedging and more.
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For education only, not financial advice. 18+. When the fun stops, stop — BeGambleAware.org.