Free Stock Trading Calculators

Stock trading is simpler mechanically than forex or crypto — no pips, no lots, no funding rates. But the core math of risk management is the same. You need to know how many shares to buy, where your stop loss should be relative to your account size, whether your historical performance is actually good or just lucky, and how long it will realistically take to compound your account to a target.

Start with position sizing. The most common mistake in stock trading is buying a round number of shares — 100 shares of a $50 stock, because it's a round number — rather than sizing based on the distance to your stop loss. The Position Size Calculator tells you exactly how many shares to buy based on what you're willing to lose if the trade goes against you.

Performance tracking matters as much as execution. After 50+ trades, the Sharpe Ratio Calculator tells you whether your returns justify the volatility you're taking on. The Expectancy Calculator combines win rate and average win/loss to give you a single number: the expected profit per dollar risked. A positive expectancy means your strategy has edge. A negative one means you're losing money slowly.

The Max Drawdown Calculator is worth checking before you increase position sizes. Doubling your position size doesn't just double your profits — it doubles your drawdowns too. Know what a realistic drawdown looks like at your current strategy performance, then decide whether you could hold through it without abandoning the plan.