Position Size Calculator for Perpetual Futures
The #1 mistake traders make is sizing positions by feel instead of math. This calculator determines exactly how large your position should be based on your account size, the risk you're willing to take, and your stop-loss distance — ensuring you never lose more than intended.
Works for all perpetual futures exchanges. Leverage affects margin efficiency, not risk — your actual risk is always determined by position size and stop distance.
Total trading capital
Percentage of account to risk on this trade
Distance from entry to stop loss
Your planned entry price
Position leverage (affects margin, not risk)
Position Size
Position Size
$5000.00
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Calculation Methodology
Position sizing ensures you never risk more than intended. The formula is simple but powerful:
Key Insight: Your risk is determined by position size and stop distance, not leverage. Higher leverage just means you need less margin to open the same position. If you size correctly, 5x and 50x have the same risk — but 50x requires less capital.
Learn more about position sizing:
Position sizing guideExample Scenario
Setup: $10,000 account, 1% risk, 2% stop, 10x leverage, $50,000 entry
What this means: If price drops 2% to $49,000 and your stop triggers, you lose exactly $100 (1% of account). The $5,000 position size ensures this, regardless of leverage.
Note: Always account for slippage. If your stop might slip 0.1%, reduce position size accordingly.
Common Mistakes & Warnings
- ⚠Confusing leverage with risk: 50x leverage doesn't mean 50x risk. Risk = position size × stop distance. Leverage only affects margin efficiency.
- ⚠Using fixed position sizes: A $1,000 position on a 1% stop is very different from a $1,000 position on a 5% stop. Always size based on risk percentage.
- ⚠Ignoring slippage: Stop orders can slip, especially in volatile markets. Add 0.1-0.5% buffer to stop distance for safety.
- ⚠Not adjusting for volatility: In high volatility, widen stops (which reduces position size). In low volatility, you can use tighter stops.
- ⚠Risking too much per trade: 1-2% is standard. Above 3% per trade, a few losses can wipe out weeks of gains.
Example Scenarios
Try these realistic scenarios to understand position sizing in different market conditions.
Scenario 1: Conservative Trader
Low risk per trade with wide stops. Ideal for beginners or traders who prioritize capital preservation.
Step-by-Step Calculation:
- Risk amount: $10,000 × 0.5% = $50
- Position size: $50 ÷ 3% = $1,667
- Margin required: $1,667 ÷ 5 = $333
- Units: $1,667 ÷ $50,000 = 0.0333 BTC
- Margin utilization: $333 ÷ $10,000 = 3.3%
What this means: You risk only $50 (0.5% of account) per trade. With a 3% stop, you can open a $1,667 position using only $333 margin (3.3% of account). This leaves plenty of capital for other trades and margin buffer.
Scenario 2: Moderate Trader
Standard 1% risk with moderate stops. The most common approach for experienced traders.
Step-by-Step Calculation:
- Risk amount: $10,000 × 1% = $100
- Position size: $100 ÷ 2% = $5,000
- Margin required: $5,000 ÷ 10 = $500
- Units: $5,000 ÷ $50,000 = 0.1 BTC
- Margin utilization: $500 ÷ $10,000 = 5%
What this means: You risk $100 (1% of account) per trade. With a 2% stop, you can open a $5,000 position using $500 margin (5% of account). This is the standard professional approach - balanced risk with good capital efficiency.
Scenario 3: Aggressive Trader
Higher risk with tight stops. Requires high win rate and strong risk management. ⚠️ High risk
Step-by-Step Calculation:
- Risk amount: $10,000 × 2% = $200
- Position size: $200 ÷ 1% = $20,000
- Margin required: $20,000 ÷ 20 = $1,000
- Units: $20,000 ÷ $50,000 = 0.4 BTC
- Margin utilization: $1,000 ÷ $10,000 = 10%
What this means: You risk $200 (2% of account) per trade. With a tight 1% stop, you can open a $20,000 position using $1,000 margin (10% of account). This is aggressive - you need high win rate and precise entries to make this work.
Edge Case Warning: With 1% stops, slippage (0.1-0.2%) can significantly impact your actual risk. A 1% stop with 0.2% slippage becomes effectively 1.2% risk, increasing your position size calculation error.
What If Variations
Explore how changing parameters affects your position size:
What if I increase leverage from 10x to 50x?
Using Scenario 2: Position size stays $5,000 (risk doesn't change), but margin drops from $500 to $100. This improves capital efficiency but doesn't change your actual risk - you still lose $100 if stopped out.
What if I widen stops from 2% to 5%?
Using Scenario 2: Position size drops from $5,000 to $2,000 (same $100 risk). Margin drops from $500 to $200. Wider stops reduce position size but give price more room to move.
What if my account grows to $20,000?
Using Scenario 2: Risk amount doubles to $200, position size doubles to $10,000, margin doubles to $1,000. Everything scales proportionally - same risk %, same stop %, same leverage.
Frequently Asked Questions
Does higher leverage mean more risk?
No — leverage affects margin efficiency, not risk. Your risk is determined by position size and stop distance. Higher leverage just means you need less collateral to open the same position.
What's a good risk percentage?
Most professional traders risk 0.5-2% per trade. This allows you to survive a losing streak. At 1% risk, you can lose 10 trades in a row and only be down 10%.
Should I adjust for volatility?
Yes — in volatile markets, your stop distance should be wider, which naturally reduces position size. The formula handles this automatically if you set appropriate stops.
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