A parlay multiplies every leg together — the odds and the risk. This calculator combines any number of legs into the true combined price, shows the payout on your stake, and — the part the bet slip does not advertise — the implied probability of the whole thing actually hitting.
Seeing that a 5-leg parlay pays +2500 but needs to hit more often than 3.8% to be profitable is the fastest cure for parlay brain. Use it before you tap "confirm".