Calculators / Back & lay
Back/lay calculator
Enter the bookmaker bet you want to cover. We return the exact lay stake, your exchange liability, and what you keep whichever way the game goes.
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Decimal equivalents: back , lay .
Lay stake
Liability
If the bet wins
If the lay wins
How it works
A back/lay pair covers both sides of the same outcome. You back at the bookmaker and lay the same selection on an exchange, sizing the lay so the two positions cancel out.
For a qualifying bet the lay stake is the back stake multiplied by the back odds, divided by the lay odds less commission. For a free bet the stake is not returned, so the numerator drops the stake and uses back odds minus one.
Commission only applies to winning lays, which is why it sits in the denominator rather than being deducted at the end.
Worked example
| Back stake | $50.00 |
| Back odds | 3.00 (+200) |
| Lay odds | 3.10 (+210) |
| Commission | 2% |
| Lay stake | $48.70 |
| Liability | $102.27 |
| Qualifying loss | −$2.27 |
$2.27 is the price of unlocking the free bet that follows. Run that free bet through the free-bet value calculator and you keep most of it.