Position Size Risk Calculator

Check the monetary and percentage risk a proposed position carries against your limits.

About Position Size Risk Calculator

Risk is the stop distance times the share count, not the position value. A large position with a tight stop can carry less risk than a small one with a wide stop. Consistent risk per trade is what makes a strategy’s expectancy meaningful; variable risk means one bad trade can erase twenty good ones.

Formula

Position Size Risk

Risk % = shares × (entry − stop) ÷ account size × 100

risk amount: Loss if the stop is hit, the only figure that matters for sizing

Worked example

With the default values below, Position Size Risk Calculator returns Risk as Share of the Account of 2.500%. Change any input above and every figure here is recalculated in your browser.

Inputs used

Shares in the positionminimum 0: 250
Entry priceminimum 0: 60
Stop-loss priceminimum 0: 55
Account sizeminimum 0.01: 50,000
Maximum risk you accept per tradeaccepts 0–100 %: 1 %

Results

Risk as Share of the Account: 2.500%
Amount at Risk: $1,250.00
Position Value: $15,000.00
Maximum Shares Within Your Limit: 100
Verdict: Over your limit — reduce to 100 shares

Step by step

1Values used
2Position Size Risk
3Risk as Share of the Account= 2.500
4Amount at Risk= 1,250.00
5Position Value= 15,000.00
6Maximum Shares Within Your Limit= 100
7Verdict= Over your limit — reduce to 100 shares

Assumptions and limits

The result is derived only from the 5 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
This is an estimate for general information and not professional financial, tax or legal advice. See the full disclaimer for the limits that apply to this kind of calculator.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is Position Size Risk calculated?

Risk % = shares × (entry − stop) ÷ account size × 100 Risk is the stop distance times the share count, not the position value. A large position with a tight stop can carry less risk than a small one with a wide stop.

Why does Position Size Risk matter?

Consistent risk per trade is what makes a strategy’s expectancy meaningful; variable risk means one bad trade can erase twenty good ones.

What values do I need to enter?

This calculator takes 5 inputs: Shares in the position, Entry price, Stop-loss price, Account size, Maximum risk you accept per trade. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.