Position Size Calculator

What is a Position Size Calculator?

A position size calculator is the single most important risk management tool for traders. Its primary goal is to determine the exact number of shares you should purchase for a trade so that if your stop loss is hit, you only lose a pre-defined, safe percentage of your total account capital.

Sizing your positions scientifically prevents account blowups and ensures that a string of consecutive losses does not severely deplete your trading pool.

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How to Use the Position Size Calculator

Follow these steps to manage capital risk per trade:

1. Total Capital (₹): Specify the total trading capital currently available in your brokerage account.
2. Risk Capital per Trade (%): Select the maximum percentage of your total capital you are willing to risk on a single trade (typically 1% to 2% is recommended).
3. Stock Entry Price (₹): Input the price at which you plan to execute your buy order.
4. Stop Loss Price (₹): Input your technical invalidation level where you will exit the trade to protect your capital.
5. Analyze Sizing Metrics: Review the exact shares to buy, max capital allocation required, and percentage of your capital deployed.
6. Leverage Indicator: If the required allocation exceeds your total capital, a warning will show indicating the leverage or risk modification needed.

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Mathematics & Sizing Formulas

The position sizing engine operates on the following mathematical steps:

Risk Amount = Total Capital * (Risk % / 100)

Stop Loss Distance = Entry Price - Stop Loss Price

Number of Shares to Buy = Risk Amount / Stop Loss Distance

Max Capital Allocation = Number of Shares to Buy * Entry Price

For example, with ₹100,000 Capital, 1% Risk, Entry at ₹100, Stop Loss at ₹95:

• Risk Amount = ₹1,000
• Stop Loss Distance = ₹5
• Shares to Buy = ₹1,000 / ₹5 = 200 Shares
• Capital Deployed = 200 * ₹100 = ₹20,000 (20% of your account is deployed, but only 1% is at risk if the trade fails).

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Frequently Asked Questions (FAQs)

Why is position sizing more important than entry timing?

Even if you have a trading system with a high win rate, without proper position sizing, one massive loss can erase weeks of gains. Sizing ensures that every loss is small and mathematically controlled, allowing your edge to play out over a large sample size of trades.

What is the 1% risk rule?

The 1% rule states that you should never risk more than 1% of your total trading account value on any single trade. For instance, if your account is worth ₹50,000, your maximum risk exposure per trade should not exceed ₹500.