Enter your trade to size the position.
How position size scales with risk & stop distance
Shares you can buy — by risk % and stop distance. Illustrative.
How to use this calculator
- Pick the direction. A long trade profits if the price rises (stop sits below entry); a short trade profits if it falls (stop sits above entry).
- Set your capital and risk per trade. Risk is the most you're willing to lose if the stop is hit. A widely used discipline is 1–2% of capital per trade — small enough that a losing streak can't sink you. Alexander Elder's Trading for a Living pairs a 2%-per-trade cap with a 6% cap on total open risk across all positions.
- Set your max per position. This is a concentration cap, and it controls something the risk % does not. Risk per trade limits your loss if the stop executes; concentration limits how much of your account sits in one stock no matter what. The gap between them is gap risk — a stop at ₹995 doesn't guarantee an exit at ₹995. On bad news a stock can open at ₹880, turning a planned 0.5% loss into a double-digit hit on whatever you deployed. Veterans size by both controls; common single-stock limits run ~10–25% of capital.
- Enter your entry and stop-loss. The distance between them is your risk per share. The tool sizes the position so that distance × your share count equals exactly the rupee risk you set — then caps it so you never exceed your cash or your per-position limit. Your position size is the smallest of the three.
- Read the headline and donut. "Position size" is how many shares to buy; "amount at risk" is your rupee loss if the stop hits. The donut shows how much of your account this one trade commits — watch that it stays inside your comfort zone.
- Add a target (optional) to see the risk-reward ratio and the breakeven win rate — the minimum share of trades you must win, at that payoff, just to avoid losing money. At 1:3 you break even winning only 25% of the time; at 1:1 you need 50%. It reframes the game: not "how often am I right," but "are my winners bigger than my losers."
- Use the table to see the core lesson: for the same rupee risk, a tighter stop buys more shares, a wider stop fewer. Position size is the lever that holds risk constant across very different setups.
A note the pros insist on: position sizing fixes your loss in advance, but only if the stop executes cleanly. Overnight gaps and fast-market slippage can blow past it, and the damage scales with how much you deployed — which is why the per-position cap matters as much as the stop. A tight stop quietly hands you a larger position, so a single gap on a concentrated holding can hurt far more than the 1% you planned. Size by risk, but cap by exposure.
All figures are illustrations based on the inputs you enter. This tool is for education only and is not investment advice or a recommendation to buy or sell any security. FactFinances is an AMFI-registered Mutual Fund Distributor (ARN-144500) and does not provide securities advisory services. Verify all figures with your broker before trading.