Calculate lay stakes, liability, and profit for qualifying bets and free bets. Works with Betfair, Smarkets, and any exchange.
Laying a bet means betting against an outcome on a betting exchange. You act as the bookmaker. If the outcome doesn't happen, you keep the backer's stake (minus commission). If it does happen, you pay out.
SNR (Stake Not Returned) free bets don't return the stake if you win — only the profit. Most free bets work this way. You'll typically retain 70-80% of the free bet value.
SR (Stake Returned) free bets return both the stake and the profit if you win. These are more valuable — you retain 90%+ of the free bet value.