How do you calculate position size?

Divide the amount you are willing to risk by the distance between your entry price and your stop-loss. If you risk $500 and your stop is $2 below entry, the position is 250 shares. The stop distance — not the account size — is what sets the share count.

What percentage should I risk per trade?

There is no universally correct number, and this is a personal decision rather than something a calculator can answer. Many published risk-management frameworks discuss 1-2% of account equity per position; the right figure depends on your circumstances, and you should consider speaking to a licensed financial adviser.

Does position size change if I move my stop-loss?

Yes, and that is the point. A wider stop means a larger loss per share, so holding your dollar risk constant requires fewer shares. A tighter stop allows more shares for the same risk.

Position-Size Calculator

Work out how many shares keep your loss within a fixed percentage of your account if your stop is hit. Everything is calculated in your browser — nothing is sent anywhere.

Account size$Risk per trade%Entry price$Stop-loss price$

Shares to buy: 20
Amount at risk: $100.00
Risk per share: $5.00
Position value: $2,000.00
% of account: 20.0%

Position sizing does not eliminate the risk of loss.

How this is calculated

shares = (account x risk%) / (entry - stop)

account: total account equity
risk%: share of equity you accept losing on this position
entry - stop: loss per share if the stop is hit

Worked example

A $25,000 account risking 1% puts $250 at risk. Entering at $48.00 with a stop at $45.00 is $3.00 of risk per share. $250 / $3.00 = 83 shares, costing $3,984 to hold.

Terms used here

Stop Loss: A pre-set price where an investor plans to exit to limit losses. A risk-management reference level, not advice.

Common questions

How do you calculate position size?: Divide the amount you are willing to risk by the distance between your entry price and your stop-loss. If you risk $500 and your stop is $2 below entry, the position is 250 shares. The stop distance — not the account size — is what sets the share count.
What percentage should I risk per trade?: There is no universally correct number, and this is a personal decision rather than something a calculator can answer. Many published risk-management frameworks discuss 1-2% of account equity per position; the right figure depends on your circumstances, and you should consider speaking to a licensed financial adviser.
Does position size change if I move my stop-loss?: Yes, and that is the point. A wider stop means a larger loss per share, so holding your dollar risk constant requires fewer shares. A tighter stop allows more shares for the same risk.

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This tool performs arithmetic on the figures you enter. It is for informational and educational purposes only, is not investment, tax or financial advice, and is not a recommendation to buy, sell, or hold any security. Projections are assumptions, not forecasts. Always do your own due diligence.

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