Forex Margin Calculator
Calculate the required margin, notional position value, and margin percentage for a forex trade based on your trade size and leverage.
Use 1 if the base matches your account currency.
Frequently Asked Questions
How is required margin calculated?
Required margin = position value ÷ leverage, where position value is your trade size in units multiplied by the pair price in your account currency.
What does 1:100 leverage mean?
With 1:100 leverage you control a position 100 times larger than your margin. A $1,000 deposit can open a $100,000 position, so the required margin is just 1% of the position value.
Is higher leverage riskier?
Yes. Higher leverage lowers the margin you need but magnifies losses just as much as gains. A small adverse price move can wipe out a heavily leveraged account.
Understanding the Forex Margin Calculator
The Forex Margin Calculator tells you how much capital your broker will set aside to open a leveraged currency trade. Enter your trade size in units of the base currency, the pair price in your account currency, and your leverage ratio. The tool instantly returns the required margin, the full notional position value you control, and the margin as a percentage of that position. It is currency-aware, fully client-side, and works for standard, mini, and micro lots. Whether you trade EUR/USD at 1:30 or an exotic pair at 1:500, it shows exactly how much of your balance is locked up as margin before you place the order.
How it works
Start by choosing a trade size. A standard lot is 100,000 units of the base currency, a mini lot 10,000, and a micro lot 1,000 — use the preset buttons or type a custom amount. Next enter the pair price, meaning the value of one base-currency unit in your account currency; leave it at 1 when the base matches your account currency. Then pick a leverage ratio such as 1:30 or 1:100, or switch to custom mode to type any value. The calculator multiplies units by price to get the notional position value, divides that by the leverage to get the required margin, and reports the inverse of leverage as the margin percentage.
Worked example
Suppose you buy one standard lot of EUR/USD — 100,000 units — with the euro priced at 1.0850 in your USD account, using 1:100 leverage. The position value is 100,000 × 1.0850 = $108,500. Dividing by 100 gives a required margin of $1,085, which is 1% of the position. Switch the leverage to 1:30 and the required margin rises to $3,616.67 (3.33%). Same trade, very different capital locked up — and the same multiplier applies to your losses.
Tips & common mistakes
- Match the pair price to your account currency. If your account is in USD and you trade GBP/USD, the price is already in USD; for pairs not quoted in your currency you must convert first.
- Required margin is what is locked, not what you can lose. Your full position value is at risk, so size positions by risk, not by the margin figure.
- Higher leverage lowers the margin but does not reduce risk — it magnifies both gains and losses on the same price move.
- Many regulators cap retail leverage (for example 1:30 on major pairs in the EU and UK), so check what your broker and jurisdiction actually allow.
- Always keep a buffer above the required margin. Brokers issue a margin call or auto-liquidate when free margin runs low.
- Use micro or mini lots to practise position sizing before scaling up to standard lots.
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Reviewed by the TopOpenTools editorial team · Last updated June 2026. These tools provide general estimates for educational purposes only and are not financial, tax, insurance, investment, or medical advice. Verify important decisions with a qualified professional.