Back-to-Lay Hedge Calculator

Lay stake and liability differ

Lay stake is the amount won before commission if the selection loses. Liability is the amount at risk if the selection wins.

The result shows both. Your exchange balance must cover the liability, not just the lay stake, so the cash needed is the back stake plus the liability.

Commission basis matters

This model charges commission on winning lay proceeds at a separate exchange. Same-exchange positions can use net-market commission and need a different calculation.

If your original back bet is on the same exchange as the lay, this tool cannot calculate the resulting net-market commission. Do not enter that position as if it were a sportsbook back bet: the commission basis can change the stake and both net outcomes.

Using it as a Betfair or Smarkets hedge calculator

To hedge on Betfair, Smarkets or another exchange, enter the lay price shown on the exchange and the commission rate on your account. Rates differ between exchanges, markets and accounts, so no default fee is assumed. Check the exchange’s settlement rules too.

This is an independent calculator. It is not affiliated with any exchange and does not know which exchanges are available where you live.

Worked example

1. Back $100 at 4.00 at a sportsbook, then lay at 3.00 on an exchange charging 2% (an illustrative rate).
2. Lay stake = $100 × 4.00 ÷ (3.00 − 0.02) = $134.23 after rounding. Liability = $134.23 × 2.00 = $268.46.
3. Selection wins: $300 − $268.46 = $31.54. Selection loses: $134.23 × 0.98 − $100 = $31.55. The one-cent gap comes from rounding the lay stake.