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Risk math · Free tool

Position sizing calculator

Compute the correct number of shares (or contracts/lots) for any trade given your account size, risk percentage, entry price, and stop level. Position size is set by the chart's stop distance — never by feel.

Current account capital
Default: 1%. Conservative: 0.5%. Aggressive: 2% (max).
Where the trade thesis is invalidated
For risk-reward ratio
For F&O instruments (e.g., Bank Nifty = 25)
Position size
— shares
Enter inputs above
Risk amount
—
Per-share risk
—
Total exposure
—
Risk-Reward
—

Formula

Position Size = (Account × Risk%) / (Entry − Stop)

The risk amount is fixed by your discipline (1% of account by default). The stop distance is fixed by the chart (a structural level beyond which the trade thesis is invalid). Position size is the arithmetic that makes them consistent. You never widen the stop to fit a larger position.

Conviction tiering

Routine setups: 0.5% risk. Good setups: 1%. High-conviction setups: 1.5–2%. Never above 2%. After three consecutive losses, halve the risk percentage until you have a winner.

Lot-size rounding

For F&O instruments, the calculated position size rounds down to the nearest whole lot. Never round up — that increases risk above the target percentage.

Educational tool. This calculator performs mathematics on inputs you provide. It does not generate trading recommendations or predict returns. Inputs do not leave your browser.