Position Size Calculator
Enter your account size, risk per trade (%), entry price, and stop-loss price. Get the position size in units and dollars so that if the stop is hit, you lose only the risk amount. For stocks and forex. Results update instantly.
How to use
Enter account size (or risk capital), risk % per trade (e.g. 1% or 2%), entry price, and stop-loss price. The calculator gives the position size so that if price hits the stop, your loss equals the risk amount. Outputs: position size in dollars, in units/shares/lots, and the risk in dollars.
e.g. 1 = risk 1% of account per trade.
Max loss = risk amount
Assumes stop is hit at exact price. Slippage and fees can increase loss.
How position size is calculated
Risk amount = account size × (risk % ÷ 100). Risk per unit = |entry price − stop price|. Position size (units) = risk amount ÷ risk per unit. Position size ($) = units × entry price. So if the stop is hit, loss = units × (entry − stop) = risk amount. For long positions, stop is below entry; for short, stop is above entry — use the absolute distance.
This tool is for education and planning only. Not investment advice.