Learn/Calculators/Risk and drawdown
Position size calculator: risk a fixed share per trade.
Decide how much of the capital one trade may lose if the stop is hit. The calculator turns that into a number of shares.
- Formula shown
- Free, nothing stored
- Share your result as a link
01How it works
In plain words.
The risk budget is the capital times the risk share. Each share loses the gap between entry and stop if the stop is hit. Dividing the budget by that gap gives the number of shares, rounded down, and never more than the capital can buy.
The formula
Risk budget = capital x risk %Shares = floor(risk budget / (entry - stop))Position value = shares x entry02Worked example
The default numbers, by hand.
Rs 10 lakh capital, 1% risk, entry Rs 500, stop Rs 470: budget Rs 10,000, Rs 30 a share at risk, 333 shares, a position of Rs 1,66,500 (16.7% of capital).
| Input | Value |
|---|---|
| Capital | ₹10,00,000 |
| Risk per trade | 1% |
| Entry price | ₹500 |
| Stop loss price | ₹470 |
| Result | Value |
|---|---|
| Shares to buy | 333 |
| Position value | ₹1.67 L |
| Rupees at risk to the stop | ₹9,990 |
| Risk budget | ₹10,000 |
| Stop distance | 6.00% |
03Key concepts
What to know before you use it.
Size from risk, not from conviction
Fixed fractional sizing keeps every trade’s loss to the same share of capital, so a run of losses shrinks positions instead of wiping out the account.
Systematic portfolios
Index style strategies usually size by weight caps instead: no stock above a set share of the portfolio. Module 4.2 covers both.
Good to know
- A wider stop means fewer shares for the same risk.
- Gaps at the open can jump past a stop; the loss can exceed the budget.
04Assumptions
What the calculator assumes.
- A long position; the stop fills at the stop price.
- Costs and slippage not included.
05Questions
Asked about the Position size calculator.
How do you calculate position size?
Shares = (capital x risk per trade) / (entry price - stop loss price), rounded down.
What risk per trade is common?
Many traders in textbooks use 0.5% to 2% of capital. It is a choice about how many losses in a row the account can absorb.
Community
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06Keep going
Learn the idea, see it applied.
More risk and drawdown calculators
Education only, not investment advice. RupeeCase is a technology platform operated by QC Alpha Technologies Pvt Ltd; it is not a fund, a PMS or a SEBI registered investment adviser. Model returns are back tested and not a promise of future returns. Figures carry the date they were checked.