American Odds vs. Decimal Odds: How to Read Both (and Convert Between Them)
Open a sportsbook in the US and you'll see odds like -150 or +240. Open one built for a European or Australian audience and the same bet shows up as 1.67 or 3.40. Same bet, same probability, same payout — just two different ways of writing the number down.
Once you know how each format actually works, switching between them is trivial. Here's the breakdown.
American Odds: Built Around $100
American odds (also called "moneyline odds") are anchored to a $100 stake:
- A negative number (like -150) tells you how much you'd need to bet to win $100. At -150, you'd risk $150 to win $100 (plus your original $150 back).
- A positive number (like +240) tells you how much you'd win on a $100 bet. At +240, a $100 bet wins $240 (plus your original $100 back).
The negative number always marks the favorite; the positive number always marks the underdog. The bigger the negative number, the heavier the favorite. The bigger the positive number, the bigger the underdog.
Decimal Odds: What Your Money Turns Into
Decimal odds skip the $100 framing entirely and just tell you the multiplier on your stake — total return, not just profit.
Bet $10 at decimal odds of 2.50, and a win returns $25 total ($10 × 2.50) — that's your original $10 back plus $15 profit. Decimal odds under 2.00 mean you're betting on a favorite (you get back less than double your stake); odds over 2.00 mean you're on an underdog.
This is part of why decimal odds are popular for parlays: to find combined odds across legs, you just multiply the decimal numbers together. American odds don't multiply that cleanly, which is the whole reason a parlay's true payout often surprises people who are used to eyeballing American odds.
Converting Between the Two
The math isn't complicated, even if it looks that way at first glance:
American → Decimal:
- If the American odds are positive: divide by 100, then add 1. (+240 → 240/100 + 1 = 3.40)
- If the American odds are negative: divide 100 by the absolute value, then add 1. (-150 → 100/150 + 1 = 1.67)
Decimal → American:
- If the decimal is 2.00 or higher: subtract 1, multiply by 100. (3.40 → (3.40 - 1) × 100 = +240)
- If the decimal is under 2.00: subtract 1, divide 100 by that number, and make it negative. (1.67 → 100 / (1.67 - 1) ≈ -150)
You don't need to memorize this — most sportsbooks and analysis tools, Parlitify included, let you toggle between American and Decimal display with one tap, so the conversion happens instantly rather than by hand.
Why the Format You Use Actually Matters
The format doesn't change what a bet pays — it changes how easy it is to compare bets at a glance. A few practical differences worth knowing:
Decimal makes parlays easier to eyeball
Since decimal odds multiply directly, you can rough out a parlay's combined odds in your head. Three legs at 1.50 each is roughly 1.50 × 1.50 × 1.50 ≈ 3.375 — no separate formula needed.
American makes favorites vs. underdogs obvious
The plus/minus split makes it immediately clear which side is favored without doing any math — useful when you're scanning a slate of games quickly.
Neither format tells you if a bet is actually good
This is the part that's easy to lose track of: odds format is presentation, not analysis. -150 and 1.67 are the identical bet with identical implied probability (about 60%) — reformatting it doesn't make it more or less likely to hit, and it says nothing about whether the market has that probability right.
What This Means for Comparing Odds
If you're shopping a line across a couple of books, or checking a game's price against your own read on it, format shouldn't matter — what matters is comparing on the same footing. Converting everything to implied probability (which is exactly what decimal odds already give you, inverted: 1 ÷ decimal odds) is usually the cleanest way to compare a moneyline, a spread, and a total side by side, regardless of which format each one happens to be displayed in.
That's the real reason Parlitify shows both formats and lets you flip between them freely — the number underneath never changes, only how it's written. Getting comfortable reading both means you're never stuck doing mental math before you can even evaluate a bet.