Open this calculator on its own page
💰 Profit/Loss Calculator
A profit in dollars is not comparable to anything. Divide it by what was at risk and it becomes a number you can add up across trades.
💡 Track Both Metrics
Dollar P&L shows absolute gain. Percentage shows efficiency. You need both to measure performance accurately.
Why Percentages Matter More Than Dollars
⚠️ The Context Problem
Absolute dollar P&L is meaningless without context:
- Hedge fund making $1M on $100M = 1% (failing)
- Retail trader making $1,000 on $10k = 10% (crushing it)
Real Comparison
Trader A: "Look at my gains!"
- Account: $100,000
- Profit: $2,000
- Return: 2%
- Trades: 50
- Avg per trade: 0.04%
Trader B: "Small gains only"
- Account: $5,000
- Profit: $750
- Return: 15%
- Trades: 30
- Avg per trade: 0.5%
Trader B is FAR more skilled, but Trader A "feels richer" because brain only sees dollars.
The Survivorship Bias Trap
Your brain remembers:
- ✓ The $500 winner (feels amazing)
- • Forgets the 8 × $100 losers
Net result: -$300, but you "feel" profitable because that one win was memorable.
✓ What Professionals Track
- Dollar P&L: Pays the bills
- Percentage Return: Measures skill
- R-Multiples: Normalizes across different setups
- Expectancy: Average profit per trade (the most important metric)
Psychology Traps in P&L Tracking
Dollar Anchoring
Your brain values $1,000 as $1,000 regardless of account size.
Result:
- $50k trader making $500/day (1%) feels "poor"
- $5k trader chasing $500/day (10%) feels "motivated"
Scaling Position Size Based on Confidence
"I'm really confident in this trade" → takes 500 shares instead of usual 100.
Problem: Confidence ≠ edge. Position size should be CONSISTENT.
Revenge Sizing
Lost $500, so next trade risks $1,000 to "make it back."
This is how accounts die. Position size should NEVER depend on previous trade.
📊 Track Your Average Win/Loss
After 50 trades, you should know:
- Average Winner: +X%
- Average Loser: -Y%
- Expectancy: $Z per trade
If you can't consistently make 1-2% per winning trade, something's wrong with your execution.
The 10% Monthly Reality Check
+10% on ONE trade = great
+10% on 50 trades = either genius or about to blow up
Why? Consistent 10% per trade means you're either taking massive risk or getting lucky. Neither is sustainable.
Track your AVERAGE return per trade over 50+ trades. That's your real edge.