Forex Margin Calculator
Work out the margin a forex position requires at a given leverage, and what it leaves free in your account.
Margin is the collateral a broker requires before it will let you open a leveraged position, and a forex margin calculator turns that requirement into a number before you place the order. Margin is not a cost — it is your own money, set aside and returned when the position closes — but it does determine how large a position your account can support.
Formula: required margin = (units × base-to-account rate) ÷ leverage
Your figures
Choose Custom to enter your broker's own pip size and contract size.
30:1 is the retail cap for major pairs in the UK and EU.
Rate to convert the pair's base currency into your account currency. Enter 1 if they are the same, or the current pair price if your account is in the quote currency.
Optional — used to show free margin.
Price increment of one pip. Only used when Instrument is Custom.
Units of the base asset in one lot. Only used when Instrument is Custom.
Results
Required margin
US$3,333.33
at 30:1 leverage
- Notional position value
- US$100,000.00
- Units of base currency
- 100,000
- Margin requirementThe inverse of leverage.
- 3.33%
What this means
Opening 1.00 lots of EUR/USD sets aside US$3,333.33 as margin. Margin is collateral held against the position, not a cost — it returns to the balance when the position closes. The full US$100,000.00 notional is what gains and losses are calculated on.
- Brokers close positions automatically when the margin level falls below their stop-out threshold.
Required margin: US$3,333.33
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Continue with these figures
About the Forex Margin calculation
This calculator estimates the margin requirement for a forex position at a given leverage ratio, and shows what that leaves free in your account.
The relationship behind any required margin calculator is simple: margin is the notional value of the position divided by the leverage. At 30:1 — the retail cap for major pairs in the UK and the EU, where the US allows 50:1, Australia 30:1 and Japan 25:1 — a standard lot requires just over 3% of its notional value. Enter the figure your own broker offers you rather than any of those; it depends on your jurisdiction, your instrument and whether you are classified as retail.
Forex Margin formula
units = lots × 100,000
notional value = units × base-to-account rate
required margin = notional value ÷ leverage
margin requirement % = (1 ÷ leverage) × 100
free margin = account balance − required margin- notional value
- The full value of the position, as opposed to the margin posted against it.
- base-to-account rate
- Rate converting the pair's base currency into your account currency. 1 when they match; the pair price when your account is in the quote currency.
- leverage
- The ratio the broker permits, e.g. 30 for 30:1.
Margin is calculated on the base currency because that is what a lot is denominated in. One standard lot of EUR/USD is 100,000 euros regardless of the price; converting that to your account currency gives the notional value the margin is a fraction of.
Higher leverage means less margin for the same position, not less risk. The gains and losses are calculated on the full notional value either way — leverage only changes how much of your own money is tied up while the position is open.
Free margin is what remains available for other positions and to absorb losses on open ones. When it runs out, brokers begin closing positions automatically.
Forex Margin: a worked example
Opening one standard lot of EUR/USD at 30:1 leverage, in a euro-denominated account so the base currency matches the account currency and the conversion rate is 1.
- Units1 × 100,000 = 100,000 EUR
- Notional value100,000 × 1 = €100,000
- Margin requirement1 ÷ 30 = 3.33%
- Required margin100,000 ÷ 30 = €3,333.33
€3,333.33 is set aside as collateral. On a €10,000 account that leaves €6,666.67 free, and uses a third of the balance as margin.
How to use the Forex Margin calculator
- Select the pair and enter the position size in lots.
- Enter the leverage your broker offers for that instrument, which is set by your jurisdiction as much as by the broker: 30:1 on major pairs for retail clients in the UK and the EU and lower on everything else, 50:1 in the US, 30:1 in Australia, 25:1 in Japan, and higher again for professionally classified clients and in jurisdictions that impose no cap.
- Set the base-to-account rate: 1 if your account currency is the pair's base currency, or the current pair price if your account is in the quote currency.
- Optionally add your account balance to see free margin and the share of the account used.
Limitations of the Forex Margin calculator
Every calculation makes assumptions. These are the ones that matter here.
- Brokers apply different leverage tiers by instrument, by position size and by account classification. Check the rate that applies to your account.
- Some brokers hold additional margin over weekends or around major news.
- Does not model margin calls or stop-outs, which depend on the broker's specific thresholds.
- Assumes a single position. Hedged positions in the same instrument may attract reduced margin.
Frequently asked questions about Forex Margin
Is margin a fee?
No. It is your own money held as collateral and returned when the position closes. The costs of holding a position are the spread, any commission, and overnight swap.
What happens if free margin runs out?
The broker issues a margin call or begins closing positions automatically once the margin level falls below its stop-out threshold. The specific level varies by broker and is set out in their terms.
Does higher leverage mean higher risk?
Higher leverage permits larger positions on the same balance, and larger positions carry more risk. The leverage itself does not change the risk of a given position size — a 0.5-lot trade risks the same amount whether the account offers 30:1 or 500:1.
Why does the calculator ask for a base-to-account rate rather than the pair price?
Because they are only the same in one case. If your account is in the quote currency, the pair price is the right figure. If your account is in the base currency, the rate is 1. For a third currency, it is neither, so asking for the rate directly keeps the calculation correct in all three cases.
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