Start with the bankroll
Your bankroll is money set aside only for betting, separate from rent, bills and savings, and small enough that losing all of it wouldn't change your life. If you can't name that number comfortably, don't bet yet.
Then set a unit
A common approach is a unit of 1% to 2% of the bankroll; cautious bettors go lower. Illustrative example: a $2,000 bankroll at 1% gives a $20 unit. A 2-unit bet is $40. The unit size calculator works it out and shows what a cold streak would cost.
Flat or scaled
Flat staking means the same size on every bet. Scaled staking means larger sizes on stronger edges and smaller ones on thinner edges, within a cap. Either way, the cap matters most: no single bet should be large enough to hurt.
Why units, not dollars
- They make results comparable: +12 units is +12 units whether a unit is $10 or $100.
- They keep sizing tied to the bankroll, so you don't creep up after a win or chase after a loss.
- They make streaks easier to read calmly (see variance).
Adjust slowly
Recalculate your unit occasionally, for example monthly, not after every result. Raising it right after a hot week, or doubling up after losses, are the two habits that most often turn a normal swing into a real problem.