TOOLS

Position Size Calculator

Position size is simply how many units (or lots) you hold on a single trade. Picking it by feel means your loss swings around every time your stop is hit.

The idea is simple. Decide how much you are willing to lose on the trade, then divide that by the stop-loss distance times the value per unit of distance. The result is a position size that keeps your risk steady. Type your numbers in below.

%
Share of balance you accept losing per trade
Distance from entry to your stop-loss
$
Dollar value per 1 unit of distance (e.g. FX 1 lot ≈ $10/pip)
Max risk on this trade
Suggested position size (units)

For forex, use pips and the value of one pip. For futures, use ticks/points and the value of one tick. The method is the same either way.

How it works & caveats

The formulas are: max risk = balance × (risk% ÷ 100), and position size = max risk ÷ (stop distance × value per unit). This is a general estimate; actual margin requirements, spreads, and minimum lot increments differ by instrument and broker. Always keep the position inside your firm’s daily loss and max drawdown limits.

This page is informational and is not investment advice.

FAQ

How do I decide a position size?
First decide how much you are willing to lose on the trade (for example 1% of your balance). Divide that amount by the stop-loss distance and the value per unit of distance, and you get the position size. This tool does the maths for you.
Does the input change for forex vs futures?
The idea is the same. For forex, enter the distance in pips and the value per unit as the value of one pip. For futures, enter the distance in ticks (or points) and the value per unit as the value of one tick (or point).
What percentage risk per trade is sensible?
Many traders keep it to 1–2% of balance per trade, but there is no single right answer. The key is to stay well within your prop firm’s daily loss and max drawdown limits.

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