Position Size Calculator
Enter account size, risk %, entry, and stop. Get the exact contract, share, or lot size to trade so a stop-out costs exactly your intended risk amount.
Inputs
Position size
Trade contracts
NaN
Theoretical exact size: NaN
Target risk amount$500.00
Stop distanceNaN
Actual risk at recommended size$NaN
Per-point multiplier$5
MES contract spec
Catch size creep before it costs you.
TradersForge logs your planned stop and recommended size on every trade — and surfaces the gap when you sized up under pressure. It's usually the second-most-common reason accounts blow up.
FAQ
- How do you calculate position size?
- Position size = Risk amount ÷ (Stop distance × Per-point multiplier). Risk amount is your account size × your risk percentage (commonly 0.5% to 2%). Stop distance is the price difference between entry and stop. Per-point multiplier varies by asset — for futures it's the contract specification ($5/point for MES, $50/point for ES); for stocks it's 1; for forex majors it's ~$10/pip per standard lot.
- What's the right risk per trade?
- Most professional discretionary traders use 0.25%-1% per trade. New traders should start at 0.25% to 0.5% — small enough that a losing streak won't do real damage. As your edge becomes proven across hundreds of trades, scaling toward 1% becomes reasonable. Above 2% per trade, sequence-of-returns risk dominates and even a profitable strategy can blow your account in a normal losing streak.
- Why does the calculator round down for futures?
- Futures contracts are integers — you can't trade 1.7 contracts. Rounding down keeps your actual risk at or below your target risk. Rounding up would over-risk the trade. The calculator shows both the theoretical exact size and the rounded-down recommendation so you can see how much you're under-risking.
- What if my recommended size rounds to 0 contracts?
- That means your stop is too wide for your risk budget — even one contract would exceed your intended risk. Three options: (1) widen the account size you're trading on, (2) tighten the stop, or (3) use micro contracts (MES instead of ES, MNQ instead of NQ, etc.) which have 1/10 the per-point multiplier and let you size precisely on smaller accounts.
- Does this work for prop firm accounts?
- Yes — use your prop firm account size as the "Account size" input. Prop firm risk per trade is typically tighter than personal-account risk because the trailing drawdown penalty is account-ending. Most successful prop firm traders use 0.25% to 0.5% per trade on funded accounts, and 0.5% to 1% during evaluations.
- How does forex position sizing differ from futures?
- Forex risk math uses pip value × lot size instead of points × contract multiplier. For most USD-quoted majors at 1 standard lot (100,000 units), 1 pip ≈ $10. At 0.1 lot (mini) ≈ $1/pip. At 0.01 lot (micro) ≈ $0.10/pip. JPY pairs and exotics have different pip values that depend on the quote currency. This calculator uses the standard $10/pip-per-lot approximation for major USD pairs.
- Can I track position sizing automatically per trade?
- Yes — TradersForge logs the planned stop alongside every trade and computes both the position size you actually used and the size you SHOULD have used given your account-level risk preferences. The discrepancy surfaces size-creep patterns (which is one of the most common discipline failures in active trading).