American odds, also called moneyline odds, are written as a number with a plus or a minus sign. They are built on a stake of 100, which makes them quick to read once you know the rule and awkward before that. This page gives the rule, the formulas and a table you can check your own sums against.
The rule
A minus number shows the stake needed to win 100. At -150 you stake $150.00 to win $100. A plus number shows the profit on a stake of 100. At +250 a $100 stake wins $250.00. The sign tells you which side is the favorite: minus is the favorite, plus is the underdog. Odds of +100 and -100 mean the same thing, an even-money bet, and sportsbooks usually write it as +100.
Working out a payout
For a plus price, profit is the stake multiplied by the price and divided by 100. For a minus price, profit is the stake multiplied by 100 and divided by the price with the minus sign dropped. The total return is the profit plus the stake you put in. The table shows the result of a $50 stake at seven common prices.
| American | Decimal | Implied probability | Profit | Total return |
|---|---|---|---|---|
| -300 | 1.33 | 75.0% | $16.67 | $66.67 |
| -150 | 1.67 | 60.0% | $33.33 | $83.33 |
| -110 | 1.91 | 52.4% | $45.45 | $95.45 |
| +100 | 2.00 | 50.0% | $50.00 | $100.00 |
| +150 | 2.50 | 40.0% | $75.00 | $125.00 |
| +300 | 4.00 | 25.0% | $150.00 | $200.00 |
| +500 | 6.00 | 16.7% | $250.00 | $300.00 |
Converting to decimal odds and probability
Decimal odds are the total return per 1 staked. From a plus price, divide by 100 and add 1. From a minus price, divide 100 by the price without its sign and add 1. Implied probability is 1 divided by the decimal odds. So +150 is 2.50 in decimal and 40% in probability, and -150 is 1.67 and 60%. To go back, a decimal figure of 2.00 or more becomes a plus price of (decimal minus 1) times 100, and a smaller one becomes a minus price of 100 divided by (decimal minus 1). Decimal 1.50 returns to -200, and decimal 3.00 returns to +200. The odds calculator runs these conversions in both directions.
Why the signs can mislead
The minus and plus signs do not say whether a bet is good or bad. They say which side the book thinks is more likely. A heavy favorite at -400 wins often and pays little, while a long shot at +800 wins rarely and pays a lot. Neither is a better bet by default. What matters is whether the chance the price implies is higher or lower than the chance you think the outcome has, after allowing for the book's margin, which the main guide explains.
Odds that move
Prices change as money comes in and as news arrives, such as an injury or a change in the weather. The price you see when you confirm the bet is the price you get, and most apps ask you to accept a changed price before they take a bet whose odds moved. A line that has moved between two apps is also a reason to compare them before placing the same bet.
Staking to win a set amount
The base of 100 is also a quick way to size a bet. To win $50 at -150, multiply the other way: 50 × 150 / 100 = $75. To win $50 at +250 you need a $20 stake, because 20 × 250 / 100 = $50. When you know how much profit you want, the price tells you how much to risk.
A quick reference for common prices
You will see the same handful of prices again and again. -110 is the standard price on spreads and totals and implies 52.4%. -200 implies 66.7% and -300 implies 75%, so a bet at -300 must win three times in four to break even. At the other end, +100 implies 50%, +200 implies 33.3% and +400 implies 20%. Knowing these anchors lets you judge a price at a glance.
Odds in other formats
Decimal odds show the total return per 1 staked, so 2.50 pays 2.50 on a stake of 1, including the stake. Fractional odds show profit against stake, so 3/2 wins 3 on a stake of 2. The three formats describe the same price: +150, 2.50 and 3/2 are one and the same. If you read betting sites from other countries, the odds calculator converts between them.
The margin inside the price
Prices are not fair. A sportsbook adjusts them so that the implied probabilities of all outcomes add up to more than 100%, and the excess is its margin. At -110 on both sides of a spread the two implied chances are 52.4% each, which sum to 104.8%. That 4.8% is the average cost of betting. The odds calculator has a margin remover for two-way markets.
What to look at on a slip
When you tap a price, the slip shows the potential payout. Check it against the formulas on this page for a few bets until you trust it. Look at whether the payout includes the stake, which it usually does, and at the date and time of the event. If you place a parlay, the slip shows one combined price, which is the product of the legs.
Next: moneyline, spread and totals.
From price to payout at three stakes
The same price scales with the stake. A winning bet at -150 pays 100 for every 150 staked, so the profit is two thirds of the stake. A winning bet at +120 pays 120 for every 100 staked, so the profit is a bit more than the stake. The table shows three prices and three stakes, with the profit and the total you get back when the bet wins.
| Price | $10 stake | $25 stake | $100 stake |
|---|---|---|---|
| -150 | $6.67 profit, $16.67 back | $16.67 profit, $41.67 back | $66.67 profit, $166.67 back |
| +120 | $12.00 profit, $22.00 back | $30.00 profit, $55.00 back | $120.00 profit, $220.00 back |
| +300 | $30.00 profit, $40.00 back | $75.00 profit, $100.00 back | $300.00 profit, $400.00 back |
In every case the stake comes back with the profit when the bet wins, and nothing comes back when it loses. A slip shows both numbers, usually as "to win" and "total return", and the gap between them is your stake.
Why there is no price between -100 and +100
American odds use two scales that meet at 100. A minus price says how much you stake to win 100. A plus price says how much you win on a stake of 100. Even money is the point where both say the same thing: -100 and +100 both mean you win what you stake. A price closer to even than that does not exist in this notation, which is why prices jump from -105 to +100 and never appear as -95 or +95. If you see a gap between -110 and +100, it is a gap in the format, not in the market.
Turning a price back into a chance by hand
You do not need a calculator to estimate the chance a price implies. For a minus price, divide the number by itself plus 100. At -180 that is 180 divided by 280, which is 64.3%. For a plus price, divide 100 by the number plus 100. At +160 that is 100 divided by 260, which is 38.5%. Those are break-even rates: the share of bets at that price you would have to win to come out even.
The two sides of a market usually add up to more than 100%. At -180 and +160 they add up to 102.7%, and the extra 2.7% is the sportsbook's margin. The article on how sportsbooks make money explains where it comes from, and the betting odds calculator does the conversion for any price.
Reading a list of prices quickly
When a screen shows many prices, sort them by the sign first. Minus prices are favorites and plus prices are underdogs. Among favorites, the bigger the number after the minus sign, the more likely the outcome: -250 is more likely than -150. Among underdogs, the bigger the number after the plus sign, the less likely the outcome: +400 is less likely than +150. That one habit stops most mistakes, such as taking -150 for a longer price than -110 because the number looks bigger.
A slip from start to finish
Say you tap Team A at -125 and type a stake of $40. The slip shows "to win $32.00" and a total return of $72.00. You confirm, and the price you saw is the price you get, even if the app moves it a minute later. If Team A wins, $72.00 lands in your balance. If Team A loses, the $40 is gone.
Now take Team B on the other side of the same game at +175 with the same $40. The slip shows "to win $70.00" and a total return of $110.00. The two bets look very different, and the sign explains why: the minus price asks for more than you win, and the plus price pays more than you stake. Neither is better in general. The question is whether the chance of winning is higher than the break-even rate of the price, and the betting odds calculator shows that rate for any price.
When the price changes before you confirm
Prices move as news arrives and as money comes in. If the price changes while the bet is on your slip, most apps stop and ask you to accept the new price or to cancel. Accepting a longer price is not a problem in itself, and accepting a shorter one costs you more per dollar. Read the new number before you accept it, and work out the break-even rate again if you plan to bet.
Frequently asked questions
What is the difference between +100 and -100?
They are the same price, an even-money bet where a win returns your stake plus an equal profit. Sportsbooks write it as +100.
Can odds be more negative than -1000?
Yes. A price such as -2000 means you risk 2000 to win 100, which is a very heavy favorite. The profit is small and the loss, if it comes, is large.
How do I find the stake needed to win a set amount?
At a minus price, multiply the amount you want to win by the price without its sign and divide by 100. To win $50 at -150, stake $75. At a plus price, multiply the target by 100 and divide by the price.
Why do two apps show different prices for the same bet?
Each sportsbook sets its own prices and margin and moves them with its own money and risk. That is why checking more than one app can save you margin.
Do American odds include my stake in the payout?
The number does not, but the payout on the slip does. Profit is the price applied to your stake, and the total return is the profit plus the stake.