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Free Lot Size Calculator for Prop Firm Traders

Proper position sizing is one of the most important — and most underestimated — skills in trading. Too large and one loss wipes out your daily drawdown limit. Too small and you're leaving money on the table. Our free Lot Size Calculator takes the guesswork out.

Free · 50+ instruments · Prop firm presets

Use the Free Lot Size Calculator →

Why Position Sizing Is Critical in Prop Trading

In a prop firm challenge, you're not just trying to make money — you're trying to make money within strict drawdown rules. A single oversized trade can blow your daily limit and end your challenge in minutes.

Using a lot size calculator ensures that every trade you take risks exactly what you planned — no more, no less. That consistency is what separates funded traders from failed challenges.

What the Calculator Takes Into Account

Account sizeThe size of your trading account or funded account.

Risk percentageThe percentage of your account you're willing to risk on this trade.

Stop loss distanceThe number of pips or points between your entry and stop loss.

Instrument tradedThe calculator supports 50+ instruments including forex majors, crosses, metals, energy and indices.

Prop firm rulesSelect your firm (FTMO, Funding Pips, Apex, E8, Topstep and more) to see the daily and max drawdown impact of your trade.

What You'll See in the Results

→Exact lot size for your trade
→Dollar risk in absolute terms
→Impact on your daily drawdown limit
→Impact on your max drawdown limit
→Visual warning if your position puts you close to limits

Calculate Your Lot Size Now

Free, instant, no account required. Works for all major prop firms and 50+ trading instruments.

Open the Lot Size Calculator →