Trading Calculators
Free interactive calculators for the math every working trader uses - sizing a position, checking a setup is worth taking, and measuring whether the edge is real once the trades are in. Plug your own numbers in, see the answer. Bookmark the ones you reach for daily.
Position Size Calculator
How many shares or contracts to buy given your account size, per-trade risk, and stop distance.
Open calculatorRisk & PsychologyR-Multiple Calculator
Convert any trade outcome into R units. Lets you compare wins and losses across different position sizes on equal footing.
Open calculatorRisk & PsychologyExpectancy Calculator
What one trade is worth on average given your win rate, average winner, and average loser - and what 100 of them compound to.
Open calculatorRisk & PsychologyKelly Criterion Calculator
The mathematically optimal fraction to risk per trade - and why the answer is always 'less than full Kelly'.
Open calculatorRisk & PsychologyDrawdown Recovery Calculator
The asymmetry that ends careers: a 50% loss takes a 100% gain to recover. Visualised at any drawdown level.
Open calculatorOptions TradingOptions P/L Calculator
Profit and loss at expiration for a single-leg call or put, with the breakeven price and the most you can make or lose.
Open calculatorRisk & PsychologyProfit Factor Calculator
Total winnings divided by total losses. One number for whether a strategy makes money, and how much room it has before it stops.
Open calculatorRisk & PsychologyRisk-Reward Ratio Calculator
Planned reward against planned risk, plus the win rate that ratio needs to break even.
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