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Forex Position Size Calculator

Trade the right size every time. Enter your account balance, the percent you will risk, your stop in pips and the pip value, then press Calculate to get your lot size.

Written by TopicDrill Editorial Team·Updated June 2026

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Trade setup

Set your risk and stop, then press Calculate.

$

Position size

0.50 lots

Amount at risk$100
Units (base currency)50,000
Mini lots5.00
Micro lots50.00
Loss per standard lot$200

Lots vs stop-loss distance

Lots at fixed risk
0.02.55.07.510.010 pips20 pips30 pips40 pips

Tighter stops allow more lots for the same $100 of risk; wider stops require fewer. Your 0.50-lot point is marked.

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How position sizing works

Position sizing flips the usual question around. Instead of asking how much you might make, you start with how much you are prepared to lose. The tool turns your risk percent into a dollar figure, then works out the largest trade whose stop-loss distance would cost exactly that amount and no more. The size adjusts automatically to your stop, so a tight stop allows a bigger position and a wide stop forces a smaller one.

The chart makes this trade-off visible. It plots how many lots you could take across a range of stop distances while keeping the same money at risk. As the stop widens the curve falls, and the marker shows where your current setup sits on that line.

A worked example

Suppose your account holds 10,000 dollars and you risk 1 percent, which is 100 dollars. Your stop loss is 20 pips away and the pip value is 10 dollars per standard lot, so one lot would lose 200 dollars if the stop is hit. Dividing 100 by 200 gives 0.5 lots, which is 5 mini lots or 50 micro lots, and 50,000 units of the base currency.

Things to keep in mind

Pip value varies with the pair and your account currency, and slippage or gaps can make a real loss larger than the stop suggests, so size with a small buffer. A balanced overview of risk management from BabyPips is a good starting point. Once you are sizing trades consistently, see how reinvested wins add up with our forex compounding calculator.

Frequently asked questions

How is forex position size calculated?

First decide the cash you are willing to lose, which is your account balance times your risk percent. Then divide that by the loss one standard lot would suffer if the stop is hit, which is your stop distance in pips times the pip value per lot. The answer is your position size in lots.

What is a pip value and why does it matter?

A pip is the smallest standard price move in a currency pair, and the pip value is what one pip is worth in your account currency for a given trade size. For a standard lot on most pairs quoted in US dollars the pip value is about 10 dollars. It matters because it converts a price distance in pips into an actual money loss.

What is the difference between standard, mini and micro lots?

A standard lot is 100,000 units of the base currency, a mini lot is 10,000 units, and a micro lot is 1,000 units. They differ only in scale, so one standard lot equals ten mini lots or one hundred micro lots. The calculator shows your size in all three so you can place the order your broker supports.

Why should I risk only a small percentage per trade?

Risking a small fixed percentage, often one or two percent, keeps any single losing trade survivable and protects you from a string of losses. If you risk too much per trade, a normal losing streak can shrink the account so far that recovering becomes very hard. Consistent small risk is what keeps you in the game.

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