In short. A scaling plan is the rule that limits how many contracts a prop firm account may trade until its balance grows: for example 2 minis (20 micros) until the account is up $1,500, then 5, then the full allowance. Trading above the current allowance is a breach on most firms.
Scaling protects the firm from a trader sizing the maximum on day one. It also sizes you: with 2 minis and a 40-tick stop on NQ you risk $800 per full stop, which on a $2,500 drawdown is three losses. The position-size calculator on this site reads the maximum contracts of each account.
Some firms scale by profit steps, others by drawdown remaining, a few not at all. The firm page shows the scaling rule from the database, or 'not stated'.
Questions traders ask
What is Scaling plan?
A scaling plan is the rule that limits how many contracts a prop firm account may trade until its balance grows: for example 2 minis (20 micros) until the account is up $1,500, then 5, then the full allowance. Trading above the current allowance is a breach on most firms.