American odds are the system for counting the sum of a potential gain of a punter, difficult to understand for many players. American odds have two types – positive and negative.
Positive American odds reflect the net profit a punter would get when betting a £100. For example, the +125 odds mean a £125 net profit for every £100. The most important thing here is to understand this is net profit only, not the whole sum of a payout. The payout will be £225 (£100 + £125), so American odds of +125 are equal to 2.25 decimal odds.
Negative American odds mean the sum a punter should bet to get a £100 net profit. For example, the -120 odds mean that for every £120 there is a £100 net profit. Hence, the payout will be £220. To transfer negative American odds into decimal odds, a punter should leave out the minus sign and divide the net profit by the odds and add one. For our example, 100/120+1 = 1,83.