Odds converter

How it works

Every odds format encodes the same thing — a price on a probability:

• American — the U.S. sportsbook default. Positive numbers (e.g. +200) show profit on a $100 bet; negative (e.g. −150) show the stake needed to win $100. Both +100 and −100 mean even money, and no line sits between them.
• Decimal — preferred in Europe and Australia. Total return per $1 staked, stake included. 2.00 = even money.
• Fractional — the UK convention. Profit/stake: 5/1 wins $5 for every $1 risked, plus the stake back.
• Implied probability — the win rate baked into the price: implied % = 100 ÷ decimal odds. A −110 line implies ~52.38%.

The no-vig (two-sided market) mode

A single line's implied probability still contains the book's margin. To see the market's true opinion, enter both sides of the same bet. With implied probabilities p₁ = 1 ÷ decimal₁ and p₂ = 1 ÷ decimal₂:

• vig = p₁ + p₂ − 1 — the overround, the book's cut.
• fair pᵢ = pᵢ ÷ (p₁ + p₂) — the no-vig probabilities, which always sum to 100%.

Example: a −110/−110 market implies 52.38% on each side — 104.76% total. The extra 4.76% is the vig, and the fair probability of each side is 52.38 ÷ 104.76 = exactly 50%. Your break-even win rate on a −110 bet is 52.38%, not 50% — that gap is what you're paying the book.

Related betting tools

• Parlay payout calculator — the real multiplier and implied probability on up to 14 legs.
• Hedge bet calculator — the exact stake that locks equal profit on a live ticket.
• Implied team total calculator — turns a spread and over/under into each team's expected points, the fastest start/sit read the betting market offers.