Forex Margin Calculator
Calculate the margin required to open a forex position given lot size, leverage, and the current price of the currency pair. Understand your true exposure before you click buy or sell.
1 standard lot, 0.1 mini, 0.01 micro
Default 100,000 units per standard lot
Current pair price (e.g., 1.0850 for EUR/USD)
Provide to see what % of your account this margin uses
Enter your lot size, quote price, and leverage, then click Calculate margin to see the required margin and notional value of the position.
For educational purposes only. Not financial advice. Read full disclaimer
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Forex Margin Formula
Notional Value = Lot Size × Contract Size × Quote Price
Required Margin = Notional Value / Leverage
Margin % = (1 / Leverage) × 100
e.g. 1 lot EUR/USD @ 1.0850, 100:1 → 1,085 margin (USD)
Worked Examples
Example 1: 1 Standard Lot EUR/USD at 100:1
You open 1 standard lot (100,000 units) of EUR/USD at 1.0850. Your broker offers 100:1 leverage.
- Notional = 1 × 100,000 × 1.0850 = $108,500
- Required Margin = $108,500 / 100 = $1,085
- Margin % = 1 / 100 = 1.00%
Example 2: 0.1 Mini Lot at 30:1
You open 0.1 mini lots (10,000 units) of GBP/USD at 1.2700 with 30:1 leverage (EU retail cap).
- Notional = 0.1 × 100,000 × 1.2700 = $12,700
- Required Margin = $12,700 / 30 ≈ $423.33
- Margin % = 1 / 30 ≈ 3.33%
How to Use This Calculator
- Enter your lot size — use the quick-pick buttons (0.01 micro, 0.1 mini, 1 standard, 5 large) or type a custom value.
- Confirm the contract size — defaults to 100,000 units per standard lot, which is the convention for most forex brokers.
- Enter the current quote price — the live price of the pair (e.g., 1.0850 for EUR/USD).
- Choose a leverage ratio — pick from common values (30, 50, 100, 200, 500) or type your broker's exact figure.
- Add your account balance (optional) — to see what percentage of your account this single position consumes in margin.
Frequently Asked Questions
- What is margin in forex trading?
- Margin is the deposit a broker requires you to set aside as good-faith collateral to open a leveraged forex position. It is not a cost or a fee — it is held while the trade is open and released when you close out. The actual size of your trade (the notional value) is much larger than the margin thanks to leverage.
- How is forex margin calculated?
- Required Margin = (Lot Size × Contract Size × Quote Price) / Leverage. For example, 1 standard lot of EUR/USD at 1.0850 with 100:1 leverage requires (1 × 100,000 × 1.0850) / 100 = 1,085 in margin (quoted in USD, the quote currency). The result is denominated in the quote currency of the pair.
- How does leverage affect margin requirements?
- Leverage and margin are inversely related. At 100:1 leverage, you need 1% margin (1 / 100). At 50:1, you need 2%. At 30:1 (the maximum for major pairs in the EU), you need ~3.33%. Higher leverage means smaller margin per trade — but it also means a smaller adverse move can wipe out your equity, so size positions deliberately.
- What is a standard, mini, and micro lot?
- A standard lot is 100,000 units of the base currency, a mini lot is 10,000 units (0.1), and a micro lot is 1,000 units (0.01). Many brokers also offer nano lots of 100 units (0.001). Smaller lot sizes let traders with smaller accounts manage risk more precisely.
- What is the difference between margin and notional value?
- Notional value is the full size of the position (lot size × contract size × price) — the total market exposure you control. Required margin is just the small fraction of that exposure your broker locks up as collateral. The gap between them is your leverage. A 100,000-unit EUR/USD trade at 1.0850 has ~$108,500 in notional value but might only need $1,085 in margin at 100:1.