A unit in forex is one piece of the base currency in a currency pair. Buy 10,000 units of EUR/USD and you are buying 10,000 euros; buy 1,000 units of GBP/USD and you are buying 1,000 British pounds. Retail brokers package units into standardized lot sizes running from 100 to 100,000, and the lot size you choose sets the cash value of every price tick in your trade.
What One Unit Represents
Every forex trade exchanges one currency for another, and the unit is the atomic measure of that exchange. One unit equals one piece of the currency listed first in the pair. In GBP/USD, one unit is one British pound. In USD/JPY, one unit is one U.S. dollar. The second currency, the quote currency, is the price tag showing what each unit costs.
That distinction has a practical consequence. When your platform confirms that you bought 10,000 units, you bought 10,000 of the base currency, regardless of whether the order was a buy or a sell of the pair. The total size of the position, called the notional value, is the number of units multiplied by the current exchange rate. Ten thousand units of EUR/USD at 1.0850 controls a position worth $10,850. That notional figure drives your margin requirement and your pip value.
Profit and loss, on the other hand, are denominated in the quote currency. If EUR/USD moves from 1.0800 to 1.0850 while you hold 10,000 units long, the gain is measured in U.S. dollars. When the quote currency matches your account currency, no conversion is needed. When it does not, your broker converts at the prevailing rate in real time.
Lot Sizes: How Units Are Packaged
Rather than typing raw unit counts into every order ticket, brokers group units into four standard lot sizes:
- Standard lot: 100,000 units of the base currency, the default for institutional and well-capitalized accounts.
- Mini lot: 10,000 units, one-tenth of a standard lot, common for intermediate retail traders.
- Micro lot: 1,000 units, the workhorse for smaller accounts that want precise control over exposure.
- Nano lot: 100 units, offered by some platforms for strategy testing at minimal risk.
Lot size has a linear effect on results. Moving from a micro lot to a mini lot multiplies exposure and gains or losses by ten.1IG Bank S.A. What Is a Lot in Forex and How Do You Calculate the Lot Size? Not every broker offers all four sizes. Some go no smaller than micro lots, so confirm what a platform supports before you open an account if granular sizing matters to you.
What Each Unit Is Worth Per Pip
A pip is the smallest standard price movement in a currency pair, and the number of units you hold sets what that movement is worth. For most pairs a pip is the fourth decimal place: a move from 1.1050 to 1.1051 is one pip. Japanese yen pairs are the exception because the yen trades at a much larger numerical value; there a pip is the second decimal place, so a move from 150.00 to 150.01 is one pip.
Multiply your position size in units by the pip increment (0.0001 for most pairs, 0.01 for JPY pairs) to get the pip value. When USD is the quote currency, the result lands in dollars:
- Standard lot (100,000 units): 100,000 × 0.0001 = $10 per pip
- Mini lot (10,000 units): 10,000 × 0.0001 = $1 per pip
- Micro lot (1,000 units): 1,000 × 0.0001 = $0.10 per pip
- Nano lot (100 units): 100 × 0.0001 = $0.01 per pip
Those familiar $10, $1, $0.10, and $0.01 figures only hold when USD is the quote currency, as in EUR/USD or GBP/USD.1IG Bank S.A. What Is a Lot in Forex and How Do You Calculate the Lot Size? Trade USD/CHF with a standard lot and a one-pip move is worth 10 Swiss francs. To convert into your account currency, divide by the current exchange rate. At a USD/CHF rate of 0.8800, one pip on a standard lot is 10 ÷ 0.8800, or roughly $11.36. On USD/JPY at 155.00, a standard-lot pip is 1,000 yen (100,000 × 0.01), or about $6.45. Most platforms handle the conversion automatically, but knowing the math keeps a 20-pip move from producing a surprising dollar result on a pair you have not traded before.
How Units Connect to Leverage and Margin
Leverage lets you control more units than your cash balance alone would buy. At 50:1, every dollar in your account controls 50 units of the base currency, so a $2,000 account could hold up to 100,000 units on a major pair. Margin is the cash your broker locks up as collateral while the position is open; it is not a fee, and it returns to your free balance when the trade closes.2FOREX.com. Margin and Pip Calculator – Help and Support
In the United States, the CFTC’s rules cap how much leverage a broker can extend on retail forex. For major currency pairs, the minimum security deposit is 2% of notional value, which translates to a ceiling of 50:1. For all other pairs the minimum is 5%, capping leverage at 20:1.3eCFR. 17 CFR 5.9 – Security Deposits for Retail Forex Transactions If a pair combines a major and a non-major currency, the broker applies the higher 5% requirement. The NFA’s regulatory guide lists EUR/USD and CAD/JPY among pairs receiving the 2% treatment and USD/MXN and BRL/MXN among those requiring 5%.4National Futures Association. Forex Transactions: Regulatory Guide These caps apply to U.S.-regulated brokers; offshore firms sometimes offer 30:1, 200:1, or higher, changing the number of units a given cash balance can support.
To find the margin required on a specific trade, divide the notional value by the leverage ratio. A 100,000-unit position with EUR/USD near 1.0000 at 50:1 requires $2,000 in margin. On a $5,000 account that leaves $3,000 of free margin to open other trades or absorb losses. If your equity falls below the required margin level, your broker either collects more funds or liquidates positions, with the trigger level varying by firm.
Sizing Units to Control Risk
Knowing lot sizes and pip values only matters when you use them to cap what you can actually lose on a trade. The standard approach is to risk a fixed percentage of the account, commonly 1% to 2%, on any single position, then work backward to the number of units.
The formula has three inputs: dollar risk per trade, stop-loss distance in pips, and pip value per unit. Divide the dollar risk by (stop-loss distance × pip value per unit) to get position size.
Take a $10,000 account risking 1% ($100) on a EUR/USD trade with a 25-pip stop. Each unit of EUR/USD carries a pip value of $0.0001. The math: $100 ÷ (25 × $0.0001) = $100 ÷ $0.0025 = 40,000 units, or four mini lots. Tighten the stop to 10 pips and the same risk budget allows 100,000 units, a full standard lot. Widen it to 50 pips and you can only hold 20,000 units.
Traders who pick a lot size first and figure out risk after have the process backward. The unit count should be the output of a risk calculation, not the starting point. Getting that sequence right means a losing streak trims positions gradually instead of draining an account in a handful of trades.
A Note on U.S. Tax Treatment
Once units start producing profit or loss, the IRS gets involved. Section 988 of the Internal Revenue Code treats forex gains and losses as ordinary income by default, taxed at your regular rate, with losses deductible against ordinary income and no annual cap. Section 988 also permits an election to treat gains and losses on forward contracts, futures, and options as capital gains, provided you identify the election before the close of the day you enter the trade.5Office of the Law Revision Counsel. 26 USC 988 – Treatment of Certain Foreign Currency Transactions Traders who elect out and use regulated futures contracts report on IRS Form 6781 under the Section 1256 split: 60% long-term and 40% short-term capital gains regardless of holding period.6IRS.gov. Gains and Losses From Section 1256 Contracts and Straddles Form 6781 Which treatment is better depends on whether you are consistently profitable; unlimited ordinary-loss deductibility can be more valuable than blended capital gains rates during a losing year.