Forex Margin Calculator
Work out the margin a trade actually ties up before you place it. Pick your lot size, enter the pair's price and your leverage, and see the full position value alongside the cash your broker will hold as collateral.
Margin required
Free bonus
Get the free Forex Sizing Cheat-Sheet
A one-page reference you can print and keep by your screen — the formulas and rules behind this calculator. We'll email it along with our Price Action Starter Kit (free lessons, no spam).
The calculator stays free — this is just a bonus reference. Unsubscribe anytime.
How to use the calculator
- Choose your trade size — standard, mini or micro lots, or type an exact number of units.
- Enter the pair's price: the value of one unit of the base currency in your account currency.
- Set your leverage (30:1, 100:1, 500:1, or whatever your broker offers).
- Read the notional position value and the required margin, with the margin rate as a percentage.
The two numbers that matter
Every leveraged forex trade has a notional value — the full size of the position — and a required margin, the slice of that value you actually put up. Notional is units multiplied by price. A standard lot of EUR/USD at 1.10 is 100,000 × 1.10 = 110,000 units of value. Margin is that notional divided by your leverage: at 30:1 you post 3,666.67 to control the whole 110,000.
The margin rate is the same thing as a percentage — 100 divided by your leverage. 30:1 is a 3.33% margin rate, 100:1 is 1%, 500:1 is 0.2%. Lower rates look efficient because they free up cash, but that freed-up cash isn't a discount. The full 110,000 is still exposed to the market, and your profit or loss is calculated on all of it.
This is where new traders get hurt. Seeing that 500:1 only needs a few hundred in margin, they open a position far larger than they'd choose if they were sizing by risk. A 1% move against a 110,000 position is 1,100 — whether you posted 3,666 or 220 in margin. The margin number tells you what you can open; it says nothing about what you should. Size by the loss you're willing to take at your stop, then check the margin fits, not the other way round.
Frequently asked questions
How is forex margin calculated?
Required margin is the notional value of the position divided by your leverage. Notional value is the number of units you trade multiplied by the pair's price in your account currency. So a 100,000-unit position (one standard lot) at a price of 1.10 has a notional of 110,000; at 30:1 leverage the margin you post is 110,000 ÷ 30 = 3,666.67. The margin rate as a percentage is simply 100 ÷ leverage — 3.33% at 30:1.
What is the difference between margin and leverage?
They are two views of the same thing. Leverage is the ratio of position size to the cash you put up — 100:1 means you control a position 100 times your margin. Margin is that cash itself, the collateral your broker holds while the trade is open. Higher leverage means a smaller margin controls the same position, which is exactly why it magnifies both gains and losses.
Does higher leverage let me trade a bigger position?
Yes, and that is the trap. With the same 3,666 of margin, 30:1 controls about 110,000 of currency while 500:1 controls over 1.8 million. The larger position moves faster in cash terms, so a small adverse price move that was survivable at low leverage can wipe out your margin at high leverage and trigger a margin call. Leverage doesn't change your edge — it only changes how quickly a mistake costs you.
Is the required margin the most I can lose?
No. Margin is what it costs to open the trade, not a cap on your loss. If the market moves against you, losses are drawn from your account balance and can exceed the margin posted; brokers close positions when equity runs low, but gaps and fast markets can leave you owing more. Size positions by the loss you can accept on a stop, not by the margin your broker will allow.
More free trading tools
The lot size to trade from your account, risk % and stop distance in pips.
Exact shares or units to trade from your account, risk % and stop.
P/L, breakeven and max profit for a single-leg call or put, with a payoff diagram.
See how a balance grows over time with regular contributions and compounding.
Get a Free Trading Guide
Pick the path that fits how you want to trade. Each guide is a practical PDF — enter your email on the page and we'll send it straight to your inbox.
Prefer to watch first? Watch the free training
Educational tool only — not financial advice. Leveraged forex and CFD trading carries a high risk of losing money quickly and is not suitable for everyone. Nothing here promises a return. Also see our trading blog.