Free Tool

Contract Size Picker

MES or ES? MNQ or NQ? Enter your account size, max drawdown, and stop-loss in ticks — and get the right contract with a concrete per-trade risk breakdown.

Why contract size matters for prop firms

The single most common reason traders fail prop firm evaluations isn't their strategy — it's position sizing. Trading one ES contract on a 50k Apex account puts $12.50 on the line per tick. A 20-tick stop is $250 per trade, and with a $2,500 trailing drawdown, just 10 losing trades in a row wipes the eval.

The MES contract (1/10th the size of ES) puts $1.25 per tick on the line. The same 20-tick stop is $25 — and you'd need 100 consecutive losing trades to blow the eval. The smaller contract gives a strategy room to breathe through normal drawdown without threatening the account.

The crossover point: when does ES make sense?

Once your drawdown room exceeds roughly $5,000 and your per-trade stop is tight enough (under 15 ticks), trading ES starts to make mathematical sense because the fills are better and the commissions are proportionally lower. The calculator above shows exactly where that line is for your specific account and stop size.