How much should I bet?
Enter your bankroll, the price and your chance that the bet wins. The calculator suggests a bet from a quarter of the Kelly formula, never more than 5% of your bankroll on one bet or 2.5% on a ticket.
Your bet
Example: a $1,000 bankroll, -110 and a 55% chance: bet $13.75, which is 1.4% of the bankroll.
Never bet the house on one bet. The suggestion is a ceiling, not a target. A smaller bet is always fine.
One pick a day, free, with its price, the book and a suggested bet size, posted at least 30 minutes before the game. Every result stays public.
See today's free pick21+ · Gamble responsibly · 1-800-GAMBLER
How the suggestion is worked out
1. Your edge. Multiply your chance by the decimal price and subtract 1. At -110 (1.91) with a 55% chance: 0.55 × 1.91 − 1 = +5%.
2. The Kelly formula. Divide the edge by the decimal price minus 1: 5% ÷ 0.91 = 5.5% of the bankroll. That is the share that grows a bankroll fastest if your chance is exactly right.
3. A quarter of it. Your chance is an estimate, and a full-size bet on a wrong estimate swings hard. A quarter grows more slowly, but its swings are a quarter the size and a wrong estimate costs far less: 5.5% ÷ 4 = 1.4%, or $13.75 on a $1,000 bankroll.
4. The cap. Never more than 5% of the bankroll on one bet, or 2.5% on a ticket, however big the edge looks.
What a unit is
One unit is 1% of your bankroll. On $1,000 a unit is $10; on $250 it is $2.50. The example above is 1.4 units. Most of our picks are about one unit, a strong one two or three, and none more than five.
Never bet the house on one bet
Losing streaks happen to good bettors. At 1% a bet, ten straight losses cost about 10% of the bankroll. At 10% a bet, they cost about 65%. Bet the same size on the big game as on a Tuesday in May. More on bankrolls and units.
Where your chance comes from
The answer is only as good as the chance you give it. If you don't have a number you trust, the price's own chance is the honest default, and at that chance the answer is always no bet. Every pick in our app shows our model's chance and a suggested size next to the price.
Questions
How much should I bet on a sports bet?
A small, fixed share of a bankroll, the money set aside only for betting. Most bets should be about 1% of it (one unit), stronger ones a little more, and no single bet over 5%.
What is the Kelly formula?
A standard formula for bet size: your edge divided by the decimal price minus 1. It gives the share of a bankroll that grows it fastest when your chance is exactly right.
Why only a quarter of the Kelly amount?
Because your chance is an estimate. A full-size bet on a chance that is a few points too high loses money over time; a quarter of it keeps the swings small and survives the mistakes.
What if the calculator says no bet?
Then the price is too short for your chance: at -110 you need more than 52.4%. Passing is the right call. Wait for a better price or a bet you rate higher.
What is a unit in betting?
One unit is 1% of your bankroll. Sizing in units keeps every bet the same share of your money through the winning weeks and the losing ones.