Unit Size Calculator

How to use it

1. 1 Enter your bankroll, the money you can afford to set aside for betting.
2. 2 Choose a unit as a percent of bankroll. Use a quick pick (0.5, 1, 2 or 3) or type your own.
3. 3 Read the dollar value of one unit and the table of 1 to 5 unit bets.

Flat betting and percentage units

A unit is your standard bet size. In flat betting you stake the same unit on most bets and only vary it a little, for example 1 unit on a normal play and 2 on a stronger one. The simplest way to set it is a percentage of your bankroll.

This calculator fixes the unit from your current bankroll. Some bettors re-set the unit as the bankroll grows or shrinks, and others hold it fixed for a season. Either is fine, as long as you decide in advance.

Why 1% to 2% is a common range

Even good bettors lose many bets in a row. With the unit fixed from your starting bankroll, ten straight losses at 1% per unit cost exactly 10% of it. At 5% per unit the same ten losses cost 50%. Small units keep you in the game through variance.

No unit size guarantees a profit. It controls how fast you can lose, not whether you win. If you want sizing based on an edge, see the Kelly criterion calculator.

Worked example

A $2,500 bankroll with a 1% unit. One unit is $25.00 and the bankroll holds 100 units. The table then shows 2 units at $50.00, 3 units at $75.00 (3% of the bankroll), 4 units at $100.00 and 5 units at $125.00 (5%).

The formula

Frequently asked questions