Free tool

Odds converter and no-vig calculator

Type odds in any box and the others convert as you type. Below it, enter both sides of a two-way market to see the sportsbook's hold and the fair, no-vig odds.

No-vig calculator both sides of one market

Hold (the book's margin)

–From the two prices on the left.
Fair odds, side A
–
Fair odds, side B
–
Fair probability, side A
–
Fair probability, side B
–

For information only. Not betting advice. 21+.

Post your picks to X, Discord and Bluesky and track your record automatically

SlipRelay posts every pick as your branded card to all your channels at once, grades it from the final score and keeps your units, ROI and win rate on a public record page.

Start free, no credit card Make a free pick card

How it works

Every odds format describes the same price. The converter turns your entry into decimal odds, then writes the other three formats from it.

American to decimal: +odds → 1 + odds/100. -odds → 1 + 100/odds
Decimal to American: 2.00 or more → +(decimal − 1) × 100. Under 2.00 → −100 ÷ (decimal − 1)
Fractional = (decimal − 1) as a fraction. Implied probability = 1 ÷ decimal

No-vig: add the implied probabilities of both sides. Anything over 100% is the sportsbook's margin. Dividing each side's probability by that total gives the fair probability, and 1 ÷ fair probability gives the fair odds.

Hold = 1 − 1 ÷ (implied A + implied B)
-110 / -110: 52.38% + 52.38% = 104.76%, hold 4.55%, fair odds +100 on both sides

Questions

How do I convert American odds to decimal?

For plus odds, divide by 100 and add 1: +150 is 2.50. For minus odds, divide 100 by the number and add 1: -110 is 1.909. Decimal odds include your stake.

What is implied probability?

The chance of winning that a price implies, before any margin is taken out. It is 1 divided by the decimal odds, so -110 implies 52.38% and +150 implies 40%.

What is the hold or vig?

The sportsbook's built-in margin. On a two-way market the implied probabilities of both sides add up to more than 100%. At -110 on both sides they add to 104.76%, which is a hold of about 4.55%.

What are no-vig fair odds?

The price each side would have with the margin removed. Divide each side's implied probability by the total of both, then convert back to odds. For -110 / -110 that is +100 on each side.

All questionsHow grading works