MarketsBench

Risk & Money Management

Position Size Calculator

Calculate how many shares, units or contracts to trade from your account balance, risk percentage, entry and stop loss. Free and instant.

%
Direction

Below entry for a long

Position size

50 units

Risk amount
$100.00
Risk per unit
$2.00
Position value
$2,500.00
% of account
25%

How this is calculated

Position size keeps the money you risk constant across trades. First we find the cash at risk, then divide by the per-unit risk:

riskAmount = balance × risk%
units = riskAmount ÷ |entry − stop|
positionValue = units × entry

For a long, per-unit risk is entry − stop; for a short it is stop − entry. The “% of account” figure shows how much buying power the resulting position uses.

Frequently asked questions

How is position size calculated?
Risk amount = balance × risk %. Units = risk amount ÷ per-unit risk, where per-unit risk is the distance from entry to stop. Position value = units × entry price.
What risk percentage should I use?
Many traders risk 0.5%–2% of account equity per trade. Smaller risk per trade means a longer losing streak is survivable. This tool defaults to 1%.
Does it work for short trades?
Yes. For shorts the per-unit risk is the distance from your stop (above entry) down to the entry price.

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