Forex position size calculator: how many lots to trade

In forex, the position size decides how much you lose if your stop-loss is hit. Choose it last, after the stop: start from the share of your account you accept to risk, measure the distance to your stop in pips, and the number of lots follows. The calculator below does it for you.

The formula

Two steps:

1. Amount at risk = account balance × risk per trade. With $1,000 and 1%, that is $10.
2. Lots = amount at risk ÷ (stop-loss distance in pips × pip value per lot). With a 20-pip stop on EUR/USD: $10 ÷ (20 × $10) = 0.05 lots.

If the stop is hit, you lose $10, the 1% you decided on. The calculator rounds down to 0.01 lots, the smallest step most brokers accept, so the real risk is never above your limit.

Lots and pips in one minute

Lot	Units of the base currency	Pip value on EUR/USD
Standard lot (1.00)	100,000	$10
Mini lot (0.10)	10,000	$1
Micro lot (0.01)	1,000	$0.10

A pip is the fourth decimal of most pairs (0.0001), and the second for pairs quoted in yen (0.01).

The pip value depends on the pair

• Pairs ending in USD (EUR/USD, GBP/USD, AUD/USD, NZD/USD): $10 per standard lot, whatever the rate.
• USD/JPY: one pip is worth 1,000 yen per lot. At a rate of 150, that is 1,000 ÷ 150 = $6.67.
• USD/CHF and USD/CAD: $10 ÷ the rate. At 0.80 on USD/CHF, that is $12.50.
• Crosses such as EUR/GBP: 10 units of the second currency (£10), converted into your account currency. If GBP/USD is at 1.30, that is $13.

Enter the pip value of your pair in the calculator; your broker usually shows it in the contract specifications. For gold, indices or crypto, check those specifications too: the size of a lot and of a “pip” varies from one broker to another.

A worked example

Your account holds $2,000 and you risk 1% per trade, so $20. On EUR/USD, the logical place for your stop is 25 pips away:

$20 ÷ (25 × $10) = 0.08 lots, or 8,000 euros.

If the chart calls for a 50-pip stop instead, the size halves to 0.04 lots. The risk stays $20: a wider stop means a smaller position, not a bigger loss.

Stop first, size second

Put the stop where your idea is proven wrong, beyond a support or a resistance, then let the size adapt. Moving the stop closer to trade bigger only makes it more likely to be hit by normal market noise. Add the spread to the stop distance: with a 1-pip spread, a 20-pip stop really costs 21 pips.

Leverage does not change your risk

Leverage decides how much margin the broker blocks to open the position, not how much you lose if the stop is hit. 0.05 lots on EUR/USD with a 20-pip stop risk $10 whether your leverage is 1:30 or 1:500. High leverage simply makes it easy to open positions far too large for your account.

Common mistakes

• Always trading the same lot size: with a fixed 0.10 lot, a 15-pip stop risks $15 and a 60-pip stop risks $60.
• Rounding up: 0.067 lots becomes 0.06, not 0.07.
• Raising the risk after a loss to win it back: keep the same percentage all session, and set a daily limit.
• Trading just before big news without thinking about it: the price can jump past the stop. See the economic calendar.

Frequently asked questions

How do I calculate my lot size in forex?

Divide the amount you accept to lose (balance × risk %) by the stop distance in pips multiplied by the pip value per lot. Example: $10 ÷ (20 × $10) = 0.05 lots.

How much should I risk per trade?

Most experienced traders risk 1 to 2% of their account per trade, so that a run of losses does not empty it. Our article on how much to invest per trade shows what 7 losses in a row do at each level.

What is the pip value of EUR/USD?

$10 per standard lot, $1 per mini lot and $0.10 per micro lot, for any pair ending in USD.

Does leverage increase my risk?

Not by itself: the risk depends on the position size and the stop. Leverage only makes it possible to open a larger position with less margin.

Forex and CFDs are high-risk products traded with leverage, and most retail accounts lose money. Only trade money you can afford to lose.