Position Size Calculator
Work out exactly how many shares to buy so a single trade never risks more than you can afford to lose.
What is position sizing?
Position sizing answers the single most important question in trading: how many shares should I buy? Instead of guessing, you decide how much money you are willing to lose if the trade goes against you, then let your stop-loss distance dictate the share quantity. Done consistently, it keeps any one losing trade small enough that your account survives long enough to let your edge play out.
Why position sizing matters
Your stop-loss defines the exit, but position size defines the rupees lost. Sizing every trade to the same fixed risk keeps a bad day from becoming a bad month.
When the maximum loss is pre-decided and small, you can let a stop-loss trigger without panic — no revenge trades, no averaging down on a losing position.
A 50% drawdown needs a 100% gain just to break even. Small consistent risk keeps your equity curve smooth so compounding can do its work.
Worked example
Suppose you have a trading account of ₹1,00,000 and you follow the 1% rule, so you are willing to lose at most ₹1,000 on any single trade. You spot a stock at an entry price of ₹500 and decide a sensible stop-loss sits at ₹485 — a risk of ₹15 per share. Dividing your ₹1,000 risk budget by the ₹15 per-share risk gives a position of 66 shares. That position is worth ₹33,000 (66 × ₹500), or about 33% of your capital — yet if the stop is hit you only lose ₹990, comfortably within your 1% limit. Notice how a tighter stop would let you buy more shares for the same rupee risk, while a wider stop forces a smaller position.
Frequently asked questions
What is a good risk per trade percentage?
Most professional and disciplined retail traders risk 1% of their capital per trade, and rarely more than 2%. Risking 1% means you would need around 20 consecutive losing trades to lose 20% of your account, which gives your strategy plenty of room to work through normal losing streaks. New traders are often advised to start at 0.5–1% while they build consistency.
Does position size include leverage or margin?
This calculator sizes your position based on per-share risk and your stop-loss, independent of leverage. If you trade with margin or in intraday products, you may be able to take the calculated position with less cash upfront — but your risk amount (the rupees lost if the stop is hit) stays exactly the same. Always size by risk, not by how much margin your broker offers.
What if the position value is more than my capital?
If your stop-loss is very tight, the formula can suggest a position worth more than your total capital. In that case you are limited by your available cash (or margin), so simply cap the position at what you can actually fund. This is a sign your stop may be too tight for the volatility of the stock — consider a wider, more realistic stop.
Why does a tighter stop-loss let me buy more shares?
Your rupee risk is fixed (e.g. ₹1,000). Position size equals that risk divided by the per-share risk, which is the distance between entry and stop. A tighter stop means a smaller per-share risk, so you can buy more shares for the same total risk. A wider stop means fewer shares. This is why your stop placement and position size must always be decided together.
Should I include brokerage and taxes in the risk?
For precise risk management you can subtract estimated brokerage, STT and other charges from your risk budget, since they add to your real loss. For most equity-delivery trades these costs are small relative to a 1% risk amount, so traders often ignore them for sizing and account for them separately. For high-frequency intraday trading, factor them in.