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Odds Converter
Convert between American, decimal, fractional odds and implied probability. Edit any field — the other three update instantly.
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Payout at these odds
Total return includes your stake back. Profit is what you win on top of it.
The number that actually matters
A single price hides the vig.
Implied probability from one price includes the book's margin. TrueLine grades every bet you log against Pinnacle's de-vigged closing line — the sharpest fair estimate in the market — so you see whether you actually beat the number.
How the math works
Every format is a different way of writing the same thing. The four conversions:
American → Decimal: +odds: 1 + odds/100 -odds: 1 + 100/|odds| Decimal → American: dec ≥ 2: (dec−1)×100 dec < 2: −100/(dec−1) Decimal → Implied %: 1 / dec × 100 Decimal → Fraction: reduce(dec − 1)
Everything is derived from one canonical decimal value, so conversions round-trip exactly: +150 → 2.50 → 40% → 3/2 → +150 with no drift. The American↔decimal functions are the same ones the TrueLine app uses, so the numbers match everywhere.
One caveat: the implied probability from a single price includes the sportsbook's vig. Both sides of a market add up to more than 100%. To recover the true, vig-free probability, use the no-vig calculator.
All math runs in your browser. We don't log or store your inputs.
Frequently asked questions
What is implied probability?
Implied probability is the win rate a set of odds is priced at — the break-even point where a bet is neither profitable nor losing long-term. It's simply 1 divided by the decimal odds. Decimal 2.50 implies 40% (1 / 2.50), meaning you'd need to win more than 40% of the time at that price to profit.
Why are decimal odds standard in Canada?
Most Canadian and European sportsbooks display decimal odds by default because they're the easiest to reason about: the decimal number is your total return per $1 staked, including your stake back. Decimal 2.50 returns $2.50 on a $1 bet ($1.50 profit). American odds are still common on US-facing books, so this converter shows both.
What does +150 mean?
American odds of +150 mean a $100 stake wins $150 in profit (total return $250). Positive American odds show the profit on a $100 bet; negative odds (e.g. -150) show how much you must stake to win $100. +150 equals decimal 2.50, a 3/2 fraction, and a 40% implied probability.
Do these implied probabilities include the vig?
Yes. The implied probability from a single price includes the sportsbook's margin (the vig or juice), so the two sides of a market add up to more than 100%. To see the true, vig-free probability, remove the margin with the no-vig calculator.