Position Size Calculator
Key takeaways
- The ₹5,000.00 risk budget (1% of ₹5.00 L) ÷ ₹5.00 risk per share allows 1,000 shares.
- A stop-loss hit costs 1,000 × ₹5.00 = ₹5,000.00 — the budget used exactly.
- Buying 1,000 shares at ₹100.00 ties up ₹1.00 L — 20% of the account, while only ₹5,000.00 is at risk to the stop.
- At 2% risk instead of 1%, the same stop distance allows 2,000 shares.
About the Position Size Calculator
The Position Size Calculator answers one narrow, mechanical question: given a rupee amount you have decided this single trade may lose, and the price at which your stop-loss sits, how many shares does that budget buy? It is the arithmetic link between a risk budget expressed as a percentage of an account and an actual order quantity.
Enter your total account capital, the percentage of it this one trade is allowed to lose, your planned entry price and your planned stop-loss price. The risk amount is capital × risk %, the risk per share is the distance from entry to stop-loss, and the position size is the first divided by the second, rounded down.
Rounding is always DOWN, never to the nearest share: a fractional share cannot be bought, and rounding up would make the position risk more than the budget it was sized from. That is why a stop-loss hit usually costs slightly less than the full risk amount — the remainder is the rounding, and the Key takeaways card names it in rupees.
"% of capital deployed" is worth reading separately from "Risk amount", because they answer different questions. A stop-loss placed very close to the entry produces a small risk per share, and a small divisor produces a large share count — this formula sizes by stop distance alone and does not cap the outlay, so the position value it returns can exceed the account itself while the risk amount stays exactly where you set it. Position size, position value and % of capital deployed all show an em dash when the entry and stop-loss prices are equal, since the risk per share would then be zero.
Frequently asked questions
How is position size calculated from risk?
Position size = ⌊(Capital × Risk %) ÷ |Entry price − Stop-loss price|⌋. The numerator is the rupee amount the trade may lose; the denominator is what one share loses if the stop is hit. The floor brackets mean the result is rounded down to a whole share.
What percentage of capital do people risk per trade?
1–2% per trade is the range most commonly cited in trading literature, on the reasoning that a run of consecutive losses at that size does not remove the ability to keep trading. It is a convention, not a rule, and this calculator applies whatever figure you enter without judging it — the slider spans 0.25% to 5% so you can see what each choice implies.
Why does the position value sometimes exceed my account capital?
Because the formula sizes purely by the distance to the stop. A stop 0.5% below the entry gives a very small risk per share, so the risk budget divides into a very large number of shares — mathematically consistent, but it assumes the capital to buy them is available. Read the "% of capital deployed" tile alongside the share count for exactly this reason.
What happens if my entry and stop-loss are the same price?
The risk per share is zero, so the division has no answer and the position size, position value and % of capital deployed all show an em dash rather than a number. The risk amount is still shown, because it depends only on your capital and your risk percentage.
Does this account for leverage, margin or brokerage?
No. The share count assumes you are buying the shares outright with the capital entered, and the risk amount does not include brokerage or taxes, which add to the cost of a losing trade. The Margin Calculator covers the leveraged case, and the Brokerage Calculator covers the charges.
How does this differ from the ATR Position Size Calculator?
Only in where the stop distance comes from. Here you supply the stop-loss price directly. The ATR version derives the distance from the instrument's own recent volatility (ATR × a multiplier) instead, which is useful when you have not chosen a specific stop price yet. The sizing arithmetic downstream is identical.
Disclaimer: This calculator is for information and education only. It is not investment advice and not a recommendation or a tip, and it does not predict prices. Trading in shares and derivatives carries a risk of loss: futures and sold options are leveraged, and a loss on them can exceed the margin paid. Brokerage differs by broker, and brokerage, taxes and exchange charges change over time. A stop-loss order is not guaranteed to fill at its price; gaps and fast markets can make a loss larger than planned. Every figure is computed solely by applying the formula and assumptions stated on this page to the inputs you entered.