Calculate lay stakes, liability and locked-in profits for qualifying bets and free bets (SNR & SR) with underlay, standard, and overlay modes.
How matched betting calculations work
Matched betting eliminates gambling risk by covering both possible sides of a sports event. You place a “back” bet at a bookmaker (betting that a selection will win) and an opposing “lay” bet at a betting exchange like Betfair, Smarkets or Matchbook (betting that the selection will not win).
Qualifying bets: When triggering a welcome bonus or reload offer, the calculator determines the exact lay stake so that your qualifying loss is minimal (often just pennies) regardless of the match result.
Free bets (SNR vs SR): Most promotional free bets are Stake Not Returned (SNR), meaning you receive only the winnings, not the free bet stake itself. SNR mode balances your returns so you lock in 70% to 80% of the free bet’s face value as withdrawable cash.
Worked example
Qualifying Bet Example
You place a £10 back bet at odds of 2.00 at a bookmaker. The exchange lay odds are 2.02 with 2% commission. The calculator outputs a lay stake of £10.00 and £10.20 exchange liability.
Your net qualifying loss is only £0.20 whether your team wins or loses.
Free Bet (SNR) Example
You place a £10 SNR free bet at back odds of 5.00, with exchange lay odds of 5.20 and 2% commission. The calculator outputs a lay stake of £7.72 and liability of £32.42.
You lock in £7.57 clear profit regardless of which outcome occurs.