Decimal Odds to American Odds: The Formulas, a Conversion Table and Examples

To convert decimal odds to American odds, check whether the decimal is 2.00 or higher. If it is, subtract 1 and multiply by 100, and the result is a plus number: 2.50 becomes +150. If it's below 2.00, divide -100 by the decimal minus 1, and you get a minus number: 1.50 becomes -200.

That's the whole conversion. Below you'll find both formulas with worked examples, a conversion table for the prices you'll see most, the reverse direction (American odds to decimal), and the rounding quirk that confuses people when 1.91 turns into -109.89.

Why the two formats look so different

Decimal odds and American odds describe the same bet in different ways. Decimal odds, the main odds format across Europe and Australia, show your total return for every $1 you bet, stake included. American odds, which US sportsbooks use, are built around $100 and show only the profit.

Plus and minus signs do the work in the American format. A plus sign shows what a $100 bet wins (positive American odds, the underdog). A minus sign shows the stake needed to win $100 (negative American odds, the favorite). Decimal has no signs at all; the dividing line is 2.00, which is even money. Above it you win more than you bet, below it you win less.

Because decimal includes the stake, the numbers never line up the way you'd guess. A decimal price of 2.50 isn't +250. It's +150, since $1.50 of the $2.50 is profit.

Decimal odds of 2.00 or more: the formula

American odds = (decimal − 1) × 100

Take 2.75. Subtract 1 to get 1.75, multiply by 100, and you have +175. A $100 bet wins $175. Check it in decimal terms: $100 × 2.75 = $275 back, which is the $100 stake plus $175 profit. Same bet.

A couple more: 3.00 becomes +200, and 4.00 becomes +300. If you can subtract 1 and move the decimal point, you can do these in your head.

Decimal odds below 2.00: the formula

American odds = −100 ÷ (decimal − 1)

Decimal odds below 2.00 are favorites, so the result is negative. Take 1.40. Subtract 1 to get 0.40, then divide -100 by 0.40, and you get -250. That means you'd risk $250 to win $100. In decimal terms, a $20 bet at 1.40 returns $28, which is $8 profit, and $8 on $20 is the same ratio as $100 on $250.

Another way to say it: divide 100 by the decimal part above 1, and put a minus sign in front. For 1.80, that's 100 ÷ 0.80 = 125, so -125.

Decimal to American odds conversion table

Here are the prices you'll see most often, with the implied probabilities (the chance each price gives the bet, before taking the vig out).

If you know +150 and -110 already, the +150 explainer and our page on -110 odds go into what those prices pay at every stake.

The rounding problem (why 1.91 isn't exactly -110)

Run 1.91 through the formula and you get -109.89, not -110. Run 1.67 and you get -149.25, not -150. Nothing is wrong with the math. Decimal odds are usually shown with two decimal places, and that rounding hides a little of the price.

The true decimal value of -110 is 1.9091, and -150 is 1.6667. A sportsbook or odds converter will usually snap the result to the nearest familiar American number, which is why the table above lists 1.91 as -110. If you're converting by hand and land a fraction off a round number, that's almost always the reason. It only matters for big stakes, but it's good to know why it happens.

Converting the other way: American odds to decimal

Going from American odds to decimal odds is just as simple.

For positive odds, divide by 100 and add 1. +130 becomes 1.30 + 1 = 2.30. For negative odds, divide 100 by the absolute value of the odds (the number without the minus sign) and add 1. -250 becomes 100 ÷ 250 = 0.40, plus 1 = 1.40.

Bettors usually convert American odds to decimal for one reason: parlays. Decimal odds multiply cleanly, so a parlay's payout is just the legs' decimal odds multiplied together. Three -110 legs are 1.909 × 1.909 × 1.909, which is about 6.96. We walk through that in working out a parlay payout.

Where fractional odds fit in

Fractional odds are the British format: profit over stake, so 3/2 means you win $3 for every $2. To get there from decimal, subtract 1 and write what's left as a fraction. 2.50 minus 1 is 1.50, which is 3/2. 1.80 minus 1 is 0.80, which is 4/5. The numerator is what you win and the denominator is what you stake. More on reading them in fractional odds explained.

Decimal odds and implied probability

Decimal odds are the easiest format to turn into a percentage. Divide 1 by the decimal price: 1 ÷ 2.50 = 40%. That's the implied probability, and comparing it with your own estimate is the start of any expected value calculation. If you think a 2.50 shot wins 45% of the time, the price is in your favor.

One catch: add up both sides of a game and you'll get more than 100%. Two sides at 1.91 come to about 104.7%. The extra is the bookmaker's margin, the vig. Prediction market prices work the same way in reverse, by the way: a contract trading at 40 cents is a 40% price, which is 2.50 in decimal and +150 in American odds. The details are in implied probability in betting.

Quick checks so you don't get it backwards

Three things catch most mistakes. Decimal odds are always above 1.00, since 1.00 would just hand your stake back. Any decimal above 2.00 has to become a plus number, and any decimal below 2.00 has to become a minus number. And the further a decimal is from 2.00, the bigger the American number gets in either direction: 1.20 is -500, 11.00 is +1000.

If a result breaks one of those rules, redo the subtraction. It's almost always the "minus 1" step that got skipped.

Put it to use

Paid2Bet shows every line in American odds, so once you can convert in your head, any price you see quoted in decimal elsewhere makes sense on our board too. You can try it with a free balance on the NFL board, no deposit needed. For the bigger picture on every odds format, our guide to how betting odds work puts it all in one place.

Paid2Bet is for players 21 and over. If betting ever stops being fun, call or text 1-800-GAMBLER for free, confidential help.