How is payout calculated in horse racing?

Every different type of bet available on a horse race is kept in a separate “pool.” In other words, exactas all go into one pool, win bets go into another, Pick 6 wagers into another, etc.

Once wagering ends, the racetrack Tote system quickly sums up the amount bet into each pool, deducts the “takeout” – the percentage of the amount wagered that the track keeps for purses, expenses and profit – and then divides the remainder of the pool by the number of winning tickets.

That determines how much each winning ticket pays in each pool.