Vig Calculator

Convert both prices to implied probabilities: −110 is 52.38%, so the two sides add up to 104.76%. The margin is the part above 100%: 4.76%. The theoretical hold — what the sportsbook keeps from a balanced book — is 1 − 1 ÷ (total implied probability, written as a decimal rather than a percentage) = 4.55%. This calculator labels that figure theoretical hold; “vig” can also mean the margin, or be used loosely for the price itself.

They measure different things. 4.76% is the margin (overround minus 100%) — how far the implied probabilities overshoot. 4.55% is the theoretical hold — the share of all money wagered the book keeps if action is balanced. Both come from the same prices; “vig” and “juice” are used loosely for either, so this calculator shows both, labelled.

Hold is the sportsbook’s cut of the total amount bet. The theoretical hold assumes the book takes bets on each side in proportion to its implied probability, so it pays out the same whichever side wins; on −150 / +130 that is 3.36%. The hold a sportsbook actually reports over a season depends on how the money really came in and on results, so it can be higher or lower.

A lower-margin price. Moving from −110 / −110 to −105 / −105 cuts the theoretical hold from 4.55% to 2.38%. The same pick at a reduced-juice price needs a lower win rate to break even.

Yes. If the margin-free (no-vig) probability is right, betting either side at the book’s own price has an EV equal to minus the hold: −4.55% on −110 / −110, or −$4.55 per $100. A bet is only positive EV if your estimated win probability multiplied by the decimal odds is above 1 — and even then the estimate can be wrong and no profit is guaranteed. Test any price with the EV calculator.