NFL Bet Line
The math here is simple. You need to know it before you bet a single dollar on an NFL moneyline. Here's how to turn any American odds price into a win probability — and why that number matters more than whether you "like" a team.
How do you convert a favorite's moneyline price to implied probability?
A minus sign means favorite. The number tells you how much you stake to win $100. So -200 means bet $200 to win $100. To find implied probability, divide the stake by the total return: 200 ÷ (200 + 100) = 66.7%. That's the market's estimate of that team's chance of winning. If you think the true probability is higher, you've got a potential edge. If you think it's lower, walk away or look at the spread instead.
Formula: Implied probability (favorite) = odds ÷ (odds + 100)
How do you convert an underdog's moneyline price?
A plus sign means underdog. The number shows what $100 wins. So +175 means win $175 on a $100 bet. The formula flips: 100 ÷ (175 + 100) = 36.4%. Add that to the favorite's 66.7% and you get more than 100%. That overage is the sportsbook's hold — the built-in edge that keeps the lights on. For a standard -110 spread price on both sides, the combined book percentage is roughly 104.8%, representing about a 4.8% theoretical hold.
Formula: Implied probability (underdog) = 100 ÷ (odds + 100)
Why does implied probability tell you if there's value?
Because price and probability are the same thing, just written differently. If you calculate -200 carries a 66.7% implied win probability but you honestly believe the favorite wins 75% of the time against this opponent, you have a value bet. If you can't make that case with film, matchup data, or injury news, you're just guessing. The market is sharp. It has to be wrong by a meaningful margin for a moneyline to pay off over time.
For a deeper look at when to back the favorite straight up versus covering a number, see What Is a Moneyline in NFL Betting and When Does It Beat the Spread? and Point Spread vs Moneyline on a Heavy NFL Favorite — Which Is Better?.
Does the same math work at every price?
Yes. Run the numbers on any line you see. -110 converts to 52.4%. -300 converts to 75%. +300 converts to 25%. Practice until you can eyeball a price and get within a point or two. If you're still getting comfortable with how American odds are displayed in the first place, How to Read NFL Betting Odds — American, Decimal, and What Each Number Costs You walks through the full format. And if you're comparing moneyline bets against spread alternatives, How the NFL Point Spread Works — and How to Bet It covers the mechanics side by side.
What's the practical takeaway?
Convert first, decide second. Never lay -200 or worse without knowing you're accepting a 66.7% implied probability — meaning one upset in three bets erases your profit. No bet guarantees a win. Availability of NFL betting lines varies by state; check your local laws before wagering. 21+ only. Gambling problem? Call 1-800-GAMBLER.