Lot Size Calculator

Lots are a unit count wearing a nickname

A lot is not an amount of money, and it is not a fixed number of units either. It is one contract of whatever instrument you are trading, and the size of that contract is set by the instrument. Say "0.35 lots" on EUR/USD and you are saying 35,000 units of euro. Say it on XAU/USD, where a contract is 100 ounces, and you are saying 35 ounces. Same words, five hundred times less metal.

That is the whole conversion. Four multiplications and one division, and the only value that is not yours is the contract size, which comes from the instrument's specification. Everything on this page — including the 68 instruments in the table further down — is quoted in USD, so the notional, the margin and the value of one price increment all arrive in dollars without a currency conversion anywhere.

The conversion is worth doing deliberately because the two numbers people hold in their heads are usually different. A platform shows volume in lots; a risk calculation produces a unit count; and a margin check needs a notional value. This page is the step between them.

Worked example: 0.35 lots of EUR/USD

Take EUR/USD at 1.1000, a 100,000-unit contract, a 1,000-unit step, and 1:30 leverage. Follow it through and check it against the panel above.

1. Units. 0.35 x 100,000 = 35,000 units. It divides exactly by the 1,000-unit step, so nothing is rounded and the platform will accept it.
2. Notional. 35,000 x 1.1000 = 38,500.00 USD of euro bought and dollar sold. This is the exposure number, not the money at risk.
3. Margin. 38,500.00 / 30 = 1,283.33 USD frozen for as long as the position is open.
4. One increment. The pip size is 0.0001, so 0.0001 x 35,000 = 3.50 USD per pip. A twenty-pip move against you is 70.00 USD.
5. Back the other way. 35,000 / 100,000 = 0.35 standard lots, which is also 3.5 mini lots or 35 micro lots — three ways of typing the same 35,000 units.

Now run the risk side of the reverse lookup on the same pair. You are willing to lose 350.00 USD and your stop sits twenty pips away:

Check it forward: 175,000 units lose 0.0001 x 175,000 = 17.50 USD per pip, and twenty pips of that is 350.00 USD — exactly the amount you started with. The notional is 175,000 x 1.1000 = 192,500.00 USD and the margin at 1:30 is 6,416.67 USD. Note how far apart the three figures sit: 350.00 at risk, 192,500.00 of exposure, 6,416.67 of margin. Anyone who sizes from the margin figure because "1.75 lots is affordable" has mixed up the third number with the first.

What one lot is, for all 68 USD-quoted instruments

This is the part no forex tutorial site publishes in full, and it is the reason a lot size on one symbol cannot be assumed from another. Every row below is taken unchanged from the contract specification file that backs this site; the last column is the smallest increment of size your broker will accept.

Read the contract size column down the page and the shape of the problem appears. Four forex pairs carry 100,000 units to a lot. The metals run 100 for gold, platinum and palladium and 5,000 for silver. Energies are 1,000 for the two crudes and 10,000 for natural gas. The twelve indices and all forty-three crypto pairs sit at 1, which is why "one lot" of US30 or BTCUSDT is one unit of the thing and not a hundred thousand of anything.

The unit step column is where tickets get rejected. Forex steps in 1,000 units, so 35,500 units is not placeable while 35,000 is. Crypto steps in 0.001, so fractional sizes are fine there. Everything else on this list steps in whole units.

Margin is what the broker freezes, not what you can lose

The margin figure on the panel answers a narrow question: how much of your account the broker will set aside while the position is open. It is derived from leverage and notional value, and it knows nothing about where your stop is. A position can take 1,283.33 USD of margin and be capable of losing 70.00 USD or 7,000.00 USD depending on the stop — the margin number is identical in both cases.

Two practical consequences follow. First, margin is the binding constraint only when it runs out: if the notional you want needs more margin than your free margin allows, the order is refused, and that is a hard stop rather than a judgement. Second, being well inside your margin limit says nothing at all about whether the size is sensible. The leverage and margin guide works through that separation in detail; the short version is that leverage sets the ceiling and risk sets the size, and they are computed in that order, never the reverse.

Gold makes the point quickly. XAU/USD has a 100-ounce contract, so 0.50 standard lots is 50 ounces. At 2,400.00 that is 120,000.00 USD of notional and 6,000.00 USD of margin at 1:20 — while a 0.01 move, the smallest quoted increment, is worth 0.01 x 50 = 0.50 USD. Twenty dollars of adverse movement in gold is 1,000.00 USD on that position, against 6,000.00 of margin. Sizes that look modest in lots can carry a lot of dollars per unit of price.

Going the other way: units to lots, and risk to lots

The two boxes under the results handle the direction people actually need mid-session.

• You already hold a position and want to describe it in the platform's volume field. Divide the units by the contract size; the panel prints standard, mini, micro and your selected type at once so you can see which one your broker's ticket is expecting.
• You know the money you can lose and the distance to the stop but not the size. Divide the loss by the stop distance expressed in price — pips multiplied by the pip size — and the unit count falls out, already rounded down to the step. The panel then shows what that costs at the stop, so you can see the rounding working in your favour rather than against it.

Rounding down matters more than it sounds. If the arithmetic gives 35,700 units against a 1,000-unit step, the tradable size is 35,000, and the loss at the stop is smaller than the budget rather than larger. Round up instead and every trade quietly runs over budget by the size of the step. On a 1,000-unit step at EUR/USD that overrun is 100.00 USD on a twenty-pip stop — a third of the budget in the example above, added by a rounding direction nobody wrote down.

Standard, mini and micro are fractions of one contract

In the common convention a lot is one contract, a mini lot is a tenth of it and a micro lot is a hundredth. On a 100,000-unit forex pair that gives 100,000 / 10,000 / 1,000 units. The panel applies that convention and fills the contract size box accordingly, which is why switching the lot type changes the number in the box rather than the number of lots.

Brokers are not consistent about it. Some platforms list 100,000 / 10,000 / 1,000 as three separate contract sizes and let you pick one as "your" contract; others keep the contract at 100,000 and express smaller sizes as fractional volume. Both produce the same units — 0.35 of a 100,000 contract and 3.5 of a 10,000 contract are both 35,000 units. The contract size box is editable precisely so you can type whichever convention your platform uses and read the units straight off it.

Where the two conventions diverge is the step. A broker that treats 10,000 as the contract usually also changes the minimum increment, and a size that is placeable under one convention can fall below the step under the other. The reference table above gives the step published for each symbol; confirm it against your own platform's specification before you rely on it.

What people call this

A forex lot size calculator, a lot calculator and a lots to units converter are all the conversion on this page, and it runs for whichever of those names you arrived under. The instrument list covers the four USD-quoted major pairs along with the metals, energies, indices and crypto pairs that are harder to convert by hand, because their contract sizes are not 100,000.

The thing people usually want next is not the conversion but the size itself — how many lots the trade is allowed to be. That starts from money and a stop rather than from a lot count, and it is what the forex position size calculator computes, with the forex sizing walkthrough going through the same arithmetic by hand. If what you need is what one increment is worth at each lot size, with your own account currency and rate, that is the pip calculator — this page shows that figure once, as one line of the conversion output, and leaves the full instrument-by-instrument table to it.

FAQ

Five things to settle before the volume field

• Take the contract size from this symbol's specification, not from the pair you traded yesterday — the word "lot" covers 100,000 units of EUR/USD and a single unit of US30.
• Say the size in units out loud before you judge it. "1.75 lots" sounds small next to 175,000 units and 192,500.00 USD of notional.
• Divide by the step once. 35,000 clears a 1,000-unit step; 35,500 does not, and a ticket that silently rounds is worse than one that refuses.
• Compare the margin against free margin, not against the balance — margin already committed to open positions is not available for this one.
• Find out which convention your platform uses for mini and micro before you trust the volume number someone quoted you.

Open the position size calculator

Where the conversion stops

This page translates between two ways of writing the same quantity and attaches the two figures that fall out of it — the margin the broker will hold and the value of one price increment. Neither of those is a decision about how much to trade. A unit count derived from a lot count is an answer to "what does this mean", and the useful question before an order is "what does my risk allow", which needs a stop distance and a budget that no conversion can supply.

It also does not price the trade. Commission, swap and the spread you pay on entry are absent from every figure here, and they are the difference between the notional you computed and the money that actually leaves the account. Sizing that includes them is worked through on the spread and commission page, and the reasoning behind picking the budget in the first place sits with the risk percentage guide.

Related guides

• Forex position size calculator — start from the money you can lose and the stop distance, and read the lot count off the other end.
• Lot sizes explained — what standard, mini, micro and nano lots are, and which ones brokers actually offer.
• Pip calculator — what one increment is worth at each lot size, in your own account currency.
• Position size by instrument — contract size, pip size and unit step for all 131 symbols.
• Leverage, margin and position size — why the margin figure is a ceiling rather than a target.
• Position size after spread and commission — the costs this page leaves out.