To convert American odds to decimal, turn the American number into profit per dollar and add 1. For a plus number, divide it by 100 and add 1, so +150 becomes 2.50. For a minus number, divide 100 by the number without its sign and add 1, so -150 becomes 1.67. That is the entire conversion, two formulas and nothing else. The reason it works is that decimal odds and American odds are the same price written two ways: American tells you profit, decimal tells you total return including your stake back.
The two formulas
American odds come in two shapes, so the conversion comes in two versions. A plus number tells you the profit on a $100 stake. A minus number tells you the stake required to profit $100. Decimal odds ignore that split entirely and report one thing: what $1 comes back as if the bet wins.
- Plus odds: decimal = (odds divided by 100) + 1. So +200 becomes 2 + 1 = 3.00, and +120 becomes 1.2 + 1 = 2.20.
- Minus odds: decimal = (100 divided by the odds, sign removed) + 1. So -200 becomes 0.5 + 1 = 1.50, and -110 becomes 0.909 + 1 = 1.91.
The "+1" in both formulas is your own money coming back. Strip it out and you are left with the profit multiplier, which is exactly what the American number was already telling you. That is why the two formats never disagree about a price. If you want the full picture across formats, the pillar guide on how to convert betting odds walks through every direction, and the betting odds converter does all of it instantly.
A worked example
Take a game where one side is +150 and the other is -150. Run both through the formulas. The +150 side becomes 150 divided by 100, which is 1.5, plus 1, which is 2.50. The -150 side becomes 100 divided by 150, which is 0.667, plus 1, which is 1.67.
Now put $100 on each and watch what the decimal number does for you. At 2.50 your bet returns $250 total, which is $150 of profit plus your $100 back. At 1.67 your bet returns $167 total, which is $67 of profit plus your stake. You did not have to remember which direction the sign pointed. You multiplied your stake by the decimal number and read the answer.
Top row: decimal odds. Middle row: the same price in American odds. Bottom row: what a $100 bet returns in total. American odds flip their sign at even money, which is decimal 2.00. Decimal odds just keep counting.
The pivot at 2.00
The ladder above shows the one landmark worth memorizing. Decimal 2.00 is even money, the point where a winning bet doubles your stake. Everything below 2.00 is a favorite and carries a minus sign in American. Everything above 2.00 is an underdog and carries a plus sign. Once you know that, you can sanity check any conversion in a second. If you turn -110 into something above 2.00, you made an arithmetic error, because a favorite can never return more than double.
This is also where the two formats genuinely differ in usefulness. American odds break at even money: the scale runs -100, -110, -200, -500, then jumps across to +100, +150, +200 going the other way. Decimal odds have no such break. They run 1.01, 1.50, 2.00, 3.00, 10.00 in one direction, which makes prices easier to sort, chart, and compare.
Why the decimal number is worth having
Three practical reasons to convert. First, payout math becomes one multiplication: stake times decimal equals total return, with no separate rule for favorites and dogs. Second, parlays become trivial, because you multiply the decimal odds of each leg together to get the parlay price. Three legs at 1.91 multiply to 6.97, which is roughly +597 in American.
Third, decimal odds sit one step from implied probability. Divide 1 by the decimal number and you have the break-even win rate the price is asking for. At 1.91 that is 52.4%. At 2.50 that is 40%. At 1.50 that is 66.7%. Knowing the win rate a price demands is the difference between betting a number and evaluating it, and the implied probability calculator runs it for you if you would rather not do the division by hand.
Where you will run into each format
American odds are the default in the United States, so that is what most US bettors see first. Decimal odds are standard across Europe, Australia, and Canada, and they are the format most betting spreadsheets, models, and odds APIs speak. If you track your bets or build a model, you will convert constantly, which is why the two formulas above are worth memorizing.
The short version
Plus odds divided by 100 plus 1. Minus odds inverted into 100 over the number plus 1. Decimal 2.00 is even money and the sign flips there. Multiply your stake by the decimal number for your total return, and divide 1 by it for the break-even win rate. Everything else about odds conversion is built on those four facts.
American odds to decimal FAQ
How do you convert American odds to decimal?
Convert plus odds by dividing the number by 100 and adding 1, and convert minus odds by dividing 100 by the number without its sign and adding 1. So +150 becomes 1.5 plus 1, which is 2.50, and -150 becomes 0.667 plus 1, which is 1.67. The added 1 represents your own stake, which decimal odds include in the return and American odds do not.
What is -110 in decimal odds?
American odds of -110 equal decimal odds of 1.91, because 100 divided by 110 is 0.909 and adding 1 gives 1.909, which rounds to 1.91. A $100 bet at 1.91 returns $191 in total, which is $91 of profit plus your $100 stake back. That price implies a break-even win rate of about 52.4%.
Is 2.00 in decimal odds the same as +100?
Yes, decimal 2.00 and American +100 are the same price, both meaning even money where a winning bet doubles your stake. It is also the exact point where American odds switch from minus to plus, so any decimal number below 2.00 is a favorite and any number above 2.00 is an underdog. That makes 2.00 the fastest way to sanity check a conversion you just ran.
Converting the number is the easy part. Getting a number worth converting is the harder one, because most prices you see already have a house margin folded in before you do the math. On BettorEdge community odds you set your own line against other real bettors with no vig sitting on top, so the decimal you calculate is the decimal you actually get. Open BettorEdge and get this price for real, peer to peer.
Build your parlay where the odds are better.
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