Hold Calculator: Measure the Full Margin on Any Two-Way Market
Hold is the total implied probability the book captured beyond 100% on a two-sided market. Standard -110/-110 game lines run about 4.76% hold. Reduced-juice books at -105/-105 cut that to roughly 2.44%. Player props often run 7-12%. Knowing the hold tells you the minimum edge you need before a bet even breaks even.
What hold means and why it varies by market type
Hold measures the combined overround on a market. If both sides were priced fairly, their implied probabilities would sum to exactly 100%. Every percentage point above 100% is margin the book extracts over the long run.
Mainstream game lines at top US books run 4-5% hold. Player props on the same books run 7-12%. Parlays compound vig with every leg - a 5-leg parlay built from -110 lines can carry 20-25% hold. Knowing the number helps you decide which markets are worth engaging.
Low hold does not mean correctly priced. A market with 3% hold might still have the true probability badly distributed between the two sides. Low hold means cheaper tax, not necessarily sharp lines.
How the overround calculation works
Convert American odds to decimal. Take the reciprocal of each decimal to get implied probability. Add both probabilities together. Subtract 100%. The remainder is the hold percentage.
At -110/-110: implied probabilities are 52.38% each, sum is 104.76%, hold is 4.76%. At -115/-105: probabilities are 53.49% and 51.22%, sum is 104.71%, hold is 4.71% - nearly identical despite the asymmetric pricing.
Three-way markets like soccer require a third leg. This calculator handles two-way markets only. For soccer, add the draw implied probability before subtracting 100%.
Step by step: using this calculator
Pull both sides from the same market snapshot at the same time. Using Bet #1 Odds from one book and Bet #2 Odds from a different book measures cross-book implied probability, not the hold of any single market.
Hold output is a quick screen. Run it before modeling any picks to know the floor edge you need to overcome.
- Enter Bet #1 Odds for the first side of the market.
- Enter Bet #2 Odds for the opposing side from the same book and same timestamp.
- Read Hold % in the results.
Worked example: -115/-105 versus -105/-105
Book A posts a game total at -115/-105. Implied probabilities: 53.49% and 51.22%, sum 104.71%, hold 4.71%.
Book B offers the same total at -105/-105. Implied probabilities: 51.22% and 51.22%, sum 102.44%, hold 2.44%.
Switching from Book A to Book B saves 2.27% hold per market. On $10,000 annual wagering volume at $100 per bet, that is roughly $227 in reduced drag from hold alone - before a single better pick.
Implied side 1
52.38%
Implied side 2
52.38%
Book hold
4.76%
Where hold matters most in practice
Player props run high hold by design. Books know prop bettors are less price-sensitive and price accordingly. A receiver reception prop at -130/-110 carries about 8% hold - nearly double a main game line.
Same-game parlays are the extreme case. Correlation adjustments and compounded margin can push SGP hold above 20%. The higher the hold, the larger the edge required to justify the bet.
Tracking average hold across the books you use gives you a real cost-per-decision number. $100 at 4.76% hold costs you $4.76 in expected loss per two-sided market decision with no edge.
What most calculator pages skip
OddsGuard is free, works in any browser with no account needed. The extension shows hold across competing books on the same market simultaneously, so you can move to the lowest-hold book on any given day rather than checking each one manually.