Point Spread
Point Spread Calculator: What Are the Odds Each Side Covers?
A point spread handicaps a lopsided game so both sides are close to a coin flip, so the price on each side reflects the probability of covering, not of winning. At Chiefs -3.5 priced -111 (1.90), the market puts the chance the Chiefs win by 4 or more at about 52.6% with vig, roughly 49% to 50% without it. Standard pricing is -110 (1.91) both sides. The point spread calculator turns both prices into cover probabilities and the vig, showing whether the line is shaded and which side holds value.
Point Spread Calculator
Point SpreadTurn spread prices into cover probability and see whether the line is shaded
Implied cover probability = 1 ÷ spread price; no-vig probability = implied ÷ (favorite implied + underdog implied)How to use the point spread calculator
Enter the spread (a label only; it does not change the math) and the price on each side. The calculator returns each side's cover probability with vig, the no-vig cover probability and the vig percentage. NFL, NBA, college football and basketball spreads are all priced the same way, and the standard price is -110 (1.91) on both sides, which works out to a 4.76% vig.
The spread is about covering, not winning. If the Chiefs are -3.5 and win by 3, they won the game but lost the bet; they need to win by 4 or more to cover. So the probability you are estimating is 'Chiefs win by 4 or more', not 'Chiefs win', and that is the number to compare with the calculator.
Half-point spreads (-3.5) cannot tie. On a whole-number spread such as -3, a Chiefs win by exactly 3 is a push: the bet is graded at odds of 1.00 and the stake is refunded. In a parlay a pushed leg is dropped at most books and the ticket pays on the remaining legs; check your sportsbook's house rules.
How to tell whether a point spread is shaded
Equal prices on both sides (-110 and -110) mean the market considers the spread balanced. Unequal prices, say -125 (1.80) on the favorite and -105 (1.95) on the underdog, mean the book rates the favorite slightly more likely to cover but would rather shade the price than move the number, often to avoid crossing a key number like 3 or 7 in the NFL.
Compare the no-vig cover probability with your own estimate. If you make the Chiefs to cover -3.5 at 56% and the market's no-vig figure is 49.3%, the favorite has value; confirm it with the expected value calculator and size it with the Kelly criterion.
Example: Chiefs -3.5 at -111 (1.90), Bills +3.5 at -118 (1.85)
- Favorite implied cover probability = 1 ÷ 1.90 = 52.6%; underdog = 1 ÷ 1.85 = 54.1%; total 106.7%, vig 6.7%.
- No-vig: favorite 49.3%, underdog 50.7%.
- The market slightly favors the Bills to stay within 3 points.
If you make the Chiefs to win by 4 or more only 45% of the time, the market's 49.3% says there is no value on the favorite. The underdog's no-vig 50.7% against your 55% is a 4.3-point edge on the Bills +3.5.
FAQ
What does a point spread mean?+
It is the margin the favorite gives the underdog before the bet is graded. At Chiefs -3.5, the Chiefs must win by 4 or more to cover; a Chiefs win by 3 or less, or a loss, means the Bills +3.5 cover. Both sides are usually priced -110.
What does -110 on a spread mean?+
You risk $110 to win $100. In decimal odds that is 1.91, an implied cover probability of 52.4% with vig, about 50% once the vig is removed. With -110 on both sides the sportsbook's vig is 4.76%, or a 4.5% hold on handle.
What happens if the game lands exactly on the spread?+
That is a push. On a whole-number spread such as -3, a win by exactly 3 means the bet is graded at 1.00 and your stake is refunded. In a parlay most sportsbooks drop the pushed leg and pay on the rest; house rules vary by book.
Should I bet the spread or the moneyline?+
It depends on what you are confident about. If you know who wins but not by how much, take the moneyline; if you expect the favorite to win comfortably, the spread pays better. Use the sportsbook hold calculator to compare the vig on each market.
What does it mean when the point spread moves?+
A change in the number or the price shows where the money is going. A move from -3.5 to -4.5 means the market has grown more confident in the favorite; a price change with the same number is the book balancing action without crossing a key number.
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Odds and vig conventions follow standard US sportsbook pricing (-110 on spreads and totals). The tax line is based on IRS Topic 419 and the Form W-2G instructions (rev. 01/2026); it is not tax advice.