Trading Calculators
Free interactive tools for trade sizing, expected value math, drawdown recovery, and long-term compound returns.
🧮 Position Size Calculator
Free position size calculator: enter account size, risk percent, and stop loss to get the exact trade amount. Built for
🧮 Expected Value Calculator
Calculate expected value (EV) per trade from win rate, average win, average loss, and number of trades. Find out if your
🧮 Drawdown & Recovery Calculator
Calculate the percentage gain needed to recover from a drawdown, plus number of winning trades required at your average
🧮 Compound Growth Calculator
Calculate compound trading returns over months/years from monthly return rate, starting capital, and optional monthly de
How to use these calculators
Each calculator solves a specific question that defines whether a strategy is viable. Use them in this order:
- Position Size Calculator — first. Before any other math, know how much you'll risk per trade. The output drives every other decision.
- Expected Value Calculator — second. Plug in your strategy's historical win rate and average win/loss. If EV is negative, the strategy loses money regardless of how disciplined you are. Stop and redesign.
- Drawdown Calculator — when in drawdown. Use it to understand the math of recovery and the realistic timeline. The most important behavioral output: drawdown >25% should reduce position size, not increase it.
- Compound Growth Calculator — for long-term planning. Plug in realistic monthly returns (2–10%/mo for skilled retail; 20%+/mo is fantasy) and a multi-year horizon. The output frames trading as a long game, not a get-rich-quick path.
What the calculators won't tell you
The calculators give exact math but cannot capture three things that determine actual outcomes:
- Variance — even with positive expected value, 10-trade losing streaks happen. The calculator output assumes long-run averages; short-run is volatile.
- Emotional execution — most strategy failures aren't math problems. They're emotional ones: revenge trading after losses, jumping to a 'better' strategy mid-test, increasing size after wins.
- Regime change — backtest data assumes future conditions resemble past ones. Markets shift (volatility, correlation, liquidity), and a strategy that worked for two years may stop working.
When to use which calculator
Before opening any new trade: Position Size Calculator with current account balance.
Before deciding to keep using a strategy: Expected Value Calculator with last 100+ trade data.
Before increasing position size after wins: Drawdown Calculator with hypothetical 30% downside.
Before mentally projecting future wealth: Compound Growth Calculator with realistic conservative inputs.