Half Point Calculator
Calculate the true cost of buying or selling half points on spreads and totals in implied probability terms.
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What Is Buying / Selling Half Points?
Many sportsbooks let you buy or sell half points on spreads and totals. Buying a half point moves the line in your favor (e.g., -3.5 to -3) but at worse odds. Selling moves it against you for better odds.
Is It Worth It?
This calculator shows you the cost of the half point in implied probability terms. Key numbers in NFL (3, 7, 10) are worth more than non-key numbers. If the probability cost is small relative to how much the half point matters, it may be a smart buy.
Key Numbers
In NFL, games most commonly land on margins of 3 and 7 points. Buying off these key numbers (e.g., moving from -3 to -2.5) is generally more valuable than buying off non-key numbers.
Frequently Asked Questions
Is buying half points worth it in sports betting?
It depends on the number. Buying off key numbers like 3 and 7 in football is often worth the extra juice because a significant percentage of NFL games land on those margins. Buying off non-key numbers is rarely worth the cost. This calculator helps you see the exact implied probability cost so you can decide.
What are key numbers in NFL betting?
Key numbers are the most common margins of victory in football. The number 3 is the most important because roughly 15% of NFL games are decided by exactly 3 points (a field goal). The number 7 is the second most important, as many games are decided by exactly one touchdown. Other notable key numbers are 6, 10, and 14.
When should you buy points on a spread?
You should consider buying points when the line crosses a key number, particularly 3 or 7 in football. For example, moving from -3.5 to -3 can be very valuable because it turns a loss into a push when the game lands on exactly 3. However, buying off non-key numbers like 4 or 5 is usually not worth the extra cost.
How much does it cost to buy a half point?
Most sportsbooks charge 10 cents (10 cents of juice) per half point, meaning the odds move from -110 to -120 for one half point. However, buying off the key number of 3 typically costs 20-25 cents, moving the odds to -130 or -135. The exact cost varies by sportsbook and by how close the line is to a key number.
Get the Edge with Optimal Bet
Our app scans sportsbook pricing across the market to expose inefficiencies and uncover +EV edges. We compare odds, surface high-value opportunities, and deliver precision alerts so you can move with conviction.
