How to Read American Betting Odds
A plain-language guide to American odds: what the plus and minus signs mean, how to work out a payout from any price, and why -110 appears on almost every line.
Updated 5 min read
American odds — also called moneyline odds — are the default format at every US and Canadian sportsbook. They look stranger than they are. Once you know that the sign tells you which of two calculations to run, there is nothing left to learn.
What the plus and minus signs mean
The sign is not a measure of how likely something is to happen in any direct sense. It tells you which side of $100 the price is quoted from.
- A negative price is the amount you must risk to win $100. At -150, you risk $150 to win $100.
- A positive price is the amount you win from a $100 risk. At +150, you risk $100 to win $150.
$100 is only a reference point. You are not required to bet it, and nothing changes proportionally if you bet $17 instead.
| Price | Risk | Profit if it wins | Total return |
|---|---|---|---|
| -200 | $100 | $50.00 | $150.00 |
| -110 | $100 | $90.91 | $190.91 |
| +100 | $100 | $100.00 | $200.00 |
| +150 | $100 | $150.00 | $250.00 |
| +400 | $100 | $400.00 | $500.00 |
The further a number sits from 100 in either direction, the more lopsided the matchup. A -2000 favourite and a +1200 underdog are describing the same mismatch from opposite ends.
Working out a payout from any price
Two formulas, picked by the sign:
Positive odds: profit = stake × (odds ÷ 100)
A $40 bet at +275 returns a profit of 40 × (275 ÷ 100) = $110, for a total return of $150.
Negative odds: profit = stake × (100 ÷ |odds|)
A $40 bet at -130 returns a profit of 40 × (100 ÷ 130) = $30.77, for a total return of $70.77.
Note the distinction between profit and return. A sportsbook's bet slip usually shows "To Win" (profit) and "Total Payout" (profit plus your returned stake). Confusing the two is the most common arithmetic mistake in betting, and it always flatters the result.
What a price says about probability
Every price carries an implied probability — the win rate at which the bet breaks even over the long run.
Positive odds: probability = 100 ÷ (odds + 100)
Negative odds: probability = |odds| ÷ (|odds| + 100)
So +150 implies 100 ÷ 250 = 40%, and -150 implies 150 ÷ 250 = 60%.
This is the number that actually matters. A price is a question: do you think this happens more often than the implied probability says? If you think a +150 underdog wins 45% of the time and the price implies 40%, that gap is the entire argument for the bet. If you have no view on the probability, you are not betting on an opinion, you are buying a lottery ticket at a known discount to fair value.
Why -110 is everywhere
Point spreads and totals are usually priced at -110 on both sides. Run the probability formula on each: 110 ÷ 210 = 52.38%.
Two outcomes at 52.38% add up to 104.76%. A market describing all possible results should sum to 100%. The extra 4.76 percentage points is the sportsbook's margin, known as the vig, juice or overround.
The practical consequence is specific and worth memorising: at -110 you need to win 52.38% of your bets to break even, not 50%. Winning exactly half of a long run of -110 bets loses 4.55% of everything you staked.
Reading a real line
A typical NFL game might be posted like this:
| Team | Spread | Moneyline | Total |
|---|---|---|---|
| Bears | +6.5 (-110) | +240 | Over 44.5 (-110) |
| Lions | -6.5 (-110) | -295 | Under 44.5 (-110) |
Three separate markets, read independently:
- Spread. The Lions must win by 7 or more. The Bears must lose by 6 or fewer, or win outright. Both at -110.
- Moneyline. Who wins, margin irrelevant. The Lions at -295 imply 74.7%; the Bears at +240 imply 29.4%. Total: 104.1%.
- Total. Combined points over or under 44.5. The half-point exists so there can be no tie.
The half-point on the spread does the same job. A spread of exactly 6 would allow a 6-point win to push, and your stake would simply be returned.
Comparing prices across sportsbooks
The same game is priced slightly differently everywhere, and those differences compound. A bet at -105 instead of -110 lowers your break-even rate from 52.38% to 51.22%. Over a season, taking the better of two available prices is worth more than most people's handicapping.
This is also why conversion matters when you are reading international sources. A Canadian or European book quoting 1.91 is offering exactly -110, and a tipster quoting 2.50 is talking about +150. Same prices, different notation.
Where to go next
- American odds vs decimal odds — the conversion both ways, and why decimal is easier for parlays.
- How to calculate parlay payouts — what happens when you multiply several of these prices together.
- Expected value in sports betting — turning an implied probability and your own estimate into a number that says whether a bet is worth making.
Frequently asked questions
- What does -110 mean in betting?
- A price of -110 means you must risk $110 to win $100. A winning $110 bet returns $210 — your $110 stake plus $100 profit. It implies a 52.38% chance of the outcome happening.
- Is +200 better than -200?
- They pay differently, not better or worse. +200 pays $200 profit on a $100 bet but implies only a 33.3% chance of winning. -200 pays $50 profit on a $100 bet and implies a 66.7% chance. The sportsbook expects the -200 side to win twice as often.
- Why are both sides of a game usually -110?
- Because the sportsbook adds a margin. Two outcomes at -110 imply 52.38% each, which totals 104.76% rather than 100%. That extra 4.76% is the vig — the sportsbook's built-in edge.
- How do I convert American odds to a payout?
- For a positive price, profit = stake × (odds ÷ 100). For a negative price, profit = stake × (100 ÷ |odds|). Add your stake back to get the total return.
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BestSlip Editorial Team
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The BestSlip editorial team writes the explanatory material behind the product: how prices are quoted, how markets are built, and what the arithmetic underneath them says. Everything published here is educational. BestSlip is not a sportsbook and does not accept bets or deposits.
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