Odds Converter

Type into any field. The other three update instantly. American, decimal, fractional and implied probability — all in one place.

How the odds converter works

Type a number into any of the four fields. The other three update automatically using the standard betting math. American odds (+150, −200) are the U.S. standard. Decimal odds (2.50) are the global default — your stake times the decimal odds gives the total payout. Fractional odds (3/2) are still used at UK racecourses. Implied probability (40%) tells you the chance the price is assigning to the outcome.

Example. A sportsbook offers Liverpool at −175 American. The converter shows that price as 1.571 decimal, 4/7 fractional, and 63.64% implied probability. A $50 stake at these odds would return $78.55 — a $28.55 profit.

Conversion formulas

American → Decimal

  • If American is positive: decimal = (American ÷ 100) + 1 → +150 becomes 2.50
  • If American is negative: decimal = (100 ÷ |American|) + 1 → −200 becomes 1.50

Decimal → American

  • If decimal ≥ 2.00: American = (decimal − 1) × 100 → 2.50 becomes +150
  • If decimal < 2.00: American = −100 ÷ (decimal − 1) → 1.50 becomes −200

Decimal → Fractional

Subtract 1 from the decimal odds, then express as a fraction in lowest terms. Decimal 2.50 → 1.50 → 3/2. Decimal 4.00 → 3.00 → 3/1.

Decimal → Implied probability

Implied probability = (1 ÷ decimal odds) × 100. Decimal 2.00 → 50%. Decimal 1.25 → 80%.

Why bettors use multiple formats

Most online sportsbooks let you display odds in any format you choose, but the difference matters when you're shopping lines across multiple books. A price posted as +110 at one book and 2.10 at another is the same price — but a price posted as +110 at one book and 2.12 at another is meaningfully better at the second. A good converter saves you from doing the math in your head while line-shopping.

Once you have your decimal price, plug it into the Odds Calculator to see the exact payout, or use the Value Calculator to check if the price has positive expected value against your model.

Frequently asked questions

For positive American odds, divide the number by 100 and add 1. So +150 becomes (150÷100)+1 = 2.50. For negative American odds, divide 100 by the absolute value and add 1. So −200 becomes (100÷200)+1 = 1.50.
Subtract 1 from the decimal odds, then express the result as a fraction. Decimal 2.50 becomes 1.50, which is 3/2. Decimal 4.00 becomes 3.00, which is 3/1. The fractional format only shows the profit ratio, not the total return.
American odds dominate U.S. sportsbooks — they look like +150 or −200. Almost every U.S.-licensed book displays American by default, but most allow you to switch to decimal in settings. Online and international books often default to decimal.
Implied probability is the percentage chance the odds suggest an outcome will happen. Calculated as 1 ÷ decimal odds × 100. Decimal odds of 2.00 imply a 50% chance. Implied probability includes the sportsbook's margin, so the "true" probability the book estimates is slightly lower.
Yes. Odds like 5/1 (read "five to one") mean you win $5 in profit for every $1 staked. The fraction's numerator is your profit and the denominator is your stake. Fractions below 1, like 1/2 ("odds-on"), mean the favorite — you win $1 profit for every $2 staked.

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