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No-Vig Calculator

Every two-sided price has the sportsbook’s margin — the vig — baked in, which is why the two sides’ implied chances add up to more than 100%. Enter a pair (or tap a live market) to see the house edge, and the true no-vig fair price with the margin removed.

Side A price

Side B price

Stake

Implied probability

Side A 52.4% · Side B 52.4%

sums to 104.8% — over 100% because of the vig

The book keeps (overround)

4.8%

hold 4.5% of stakes

True no-vig fair price

Side A +100 · Side B +100

the margin removed — the two fair chances sum to exactly 100%

The vig on your bet

On $100.00 at -110 (Side A), a fair no-vig book (+100) would pay you $9.09 more over the long run — that gap is the vig.

Or tap a live market

What the vig is, and why fair ≠ book

• The two sides add up to more than 100%. Convert each American price to an implied probability and sum them: a −110/−110 line implies 52.38% + 52.38% = 104.8%. That extra 4.8% is the overround — the book’s built-in margin.
• Overround vs hold. The overround is the sum minus 100%. The hold is that margin as a share of the money bet — the commonly-quoted “≈4.5% on a −110 line.” Both describe the same house edge; this tool shows both, labeled.
• The no-vig fair price. Removing the margin rescales the two implied chances so they sum to exactly 100% — that’s the fair line. A −110/−110 market de-vigs to a true 50/50, i.e. a fair price of +100 on each side.
• Honest de-vig only. The math averages implied probabilities, never the American numbers, and reuses the same audited de-vig utilities as the rest of the site. It shows a cost, not a prediction — it says nothing about who wins.

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