American to Decimal Odds Converter
Convert American moneyline odds (e.g. +150 or -110) into decimal odds, fractional odds, and implied probability. Use this when comparing lines across sportsbooks or calculating exact payouts for a bet.
About this calculator
American odds come in two forms. Positive odds (e.g. +150) show how much profit you earn on a $100 bet, while negative odds (e.g. -110) show how much you must risk to win $100. To convert to decimal odds: for positive odds, Decimal = (americanOdds / 100) + 1; for negative odds, Decimal = (100 / |americanOdds|) + 1. Total payout = Decimal Odds × Bet Amount. So a $50 bet at +150 gives Decimal = 1.50 + 1 = 2.50, and a total return of $125. Implied probability = 1 / Decimal Odds × 100%. Understanding these conversions helps you quickly spot value and compare odds across bookmakers that display lines in different formats.
How to use
Suppose you see American odds of +200 and want to bet $100. Step 1 — Enter americanOdds = +200 and betAmount = $100. Step 2 — The calculator applies: Decimal = (200 / 100) + 1 = 3.00. Step 3 — Total payout = 3.00 × $100 = $300 (profit of $200). Step 4 — Implied probability = 1 / 3.00 = 33.3%. Now try -150 with a $50 bet: Decimal = (100 / 150) + 1 = 1.667; payout = 1.667 × $50 = $83.33 (profit of $33.33).
Frequently asked questions
How do I convert American odds to decimal odds manually?
For positive American odds, divide the odds by 100 and add 1. For example, +250 becomes (250/100) + 1 = 3.50. For negative American odds, divide 100 by the absolute value of the odds and add 1. For example, -120 becomes (100/120) + 1 = 1.833. Decimal odds always represent the total return per unit staked, including your original stake.
What does implied probability mean in sports betting odds?
Implied probability is the likelihood of an outcome as reflected by the bookmaker's odds. It is calculated as 1 divided by the decimal odds, expressed as a percentage. For example, decimal odds of 2.50 imply a 40% chance of winning. If you believe the true probability is higher than the implied probability, the bet may offer positive expected value.
Why do American odds use positive and negative numbers?
The sign indicates which side of the bet you are on relative to even money. Positive odds mean the outcome is considered less likely than 50/50 — you win more than you risk. Negative odds mean the outcome is favored — you must risk more than you stand to win. The benchmark is always $100: positive odds show profit on a $100 bet, while negative odds show the stake needed to profit $100.