How to calculate lot size in forex, in three steps
- Decide what you can lose. Account balance × risk %. A $10,000 account risking 1% is $100.
- Set the stop from the chart, in pips. Measure the distance from your entry to the price where the trade idea is wrong, for example 35 pips. Do this before you think about size. Moving the stop closer just to fit a bigger lot is the most common way to turn a plan into a gamble.
- Divide by what a pip is worth. One pip on one standard lot of EUR/USD is $10 for a USD account, so the size is $100 ÷ (35 × $10) = 0.2857 lots. Round down to the lot step your broker allows: 0.28 lots, which risks $98.00.
Standard, mini and micro lots
A standard lot is 100,000 units of the base currency, a mini lot 10,000 and a micro lot 1,000. The calculator also splits your answer into those pieces: 0.28 lots is 0 standard + 2 mini + 8 micro. Many platforms take the answer directly as 0.01-lot steps, so the split is a way to sanity-check it.
Why the pair matters: the value of a pip
The only part of the formula that changes between instruments is the value of one pip. When the quote currency is your account currency (EUR/USD with a USD account) it is fixed. When your account currency is the base (USD/JPY) it moves with the price: 1,000 yen per lot ÷ 150 is $6.67. For crosses (EUR/GBP, GBP/JPY) you need a conversion rate. The three modes above handle all of them, and the pip value calculator shows the maths for one pip in more detail.
How brokers differ, and what to check
- Lot size. 100,000 units is standard for forex, but gold is often 100 ounces per lot and index CFDs often 1 unit or $1 per point. Change the units field to match your broker's contract specification.
- Minimum lot and step. Many brokers allow 0.01 lot, some 0.1 or 1, and a few offer cent or nano accounts at 0.001. The calculator rounds down to your step, never up. With a 0.1 step the same EUR/USD trade is 0.20 lots ($70.00 real risk) instead of 0.28 ($98.00).
- Account currency. A pip is worth $10 only with a USD account on a USD-quoted pair. Other combinations need a conversion, which the base and cross modes do.
- Margin is separate. Lot size sets the risk of the stop. The margin your broker holds depends on leverage and is not part of this calculation; the leverage figure shows how large the position is relative to the account, and the margin calculator shows the margin, the margin level and how far price can move before a margin call or stop-out.
The lot size formula
value of one pip per lot = lot units × pip size × quote→account rate
lot size = risk amount ÷ (stop in pips × value of one pip per lot)
rounded down to a multiple of the lot stepThe quote→account rate is 1 when the quote currency is your account currency, 1 ÷ price when your account currency is the base, and a cross rate otherwise. Real risk = rounded lot size × stop in pips × value of one pip per lot.
Worked examples
EUR/USD, $10,000, 1% risk, 35 pip stop
Risk is $100. One pip on one lot is $10, so the exact size is 100 ÷ (35 × 10) = 0.2857 lots, and rounded down to 0.01 it is 0.28 lots. Real risk: $98.00, position value $30,380, leverage 3.0×.
USD/JPY at 150, $10,000, 1% risk, 30 pip stop
The pip is earned in yen: 1,000 yen per lot, which is $6.67 at 150. The size is 100 ÷ (30 × 6.6667) = 0.5000, so 0.50 lots, a position worth $50,000.
A $500 account: when 0.01 lot is the floor
Risking 1% of $500 is $5. On EUR/USD with a 20 pip stop, one micro lot (0.01) risks 20 × $0.10 = $2, so the exact size of 0.025 rounds down to 0.02 lots and risks $4.00. If the stop were 100 pips, even 0.01 lot would risk $10, twice the limit, and the answer is zero: use a tighter stop or a smaller size, not a bigger risk.
Gold: a lot of 100 ounces
With 100 ounces per lot, a $1 move is $100 per lot. A $15 stop on a $10,000 account at 1% gives 100 ÷ (15 × 100) = 0.0667, rounded down to 0.06 lots and $90.00 of real risk. One full lot would risk $1,500 on that stop.
A cross pair: GBP/JPY with a USD account
The pip is 1,000 yen per lot, converted at USD/JPY 150 ($6.67). A 40 pip stop at 1% of $10,000 gives 0.3750, so 0.37 lots, far smaller than the same risk on EUR/USD with a 20 pip stop, because the stop is wider and the pip worth less.
Frequently asked questions
How do I find my lot size?
Use lot size = (balance × risk %) ÷ (stop in pips × pip value per lot). With $10,000, 1% risk, a 35 pip stop and $10 per pip per lot on EUR/USD that is 0.2857, so 0.28 lots. The calculator above does it for any pair and shows the working.
How many lots should I trade with $1,000, $5,000 or $10,000?
There is no fixed number, because the stop distance sets it. For EUR/USD with a 20 pip stop at 1% risk the answer is 0.05 lots for $1,000, 0.25 for $5,000 and 0.50 for $10,000. Change the stop to 40 pips and every figure halves.
What is the difference between a standard, mini and micro lot?
A standard lot is 100,000 units of the base currency, a mini lot is 10,000 and a micro lot is 1,000. In lot terms they are 1.00, 0.10 and 0.01. The calculator splits your result into those pieces.
Why does my broker show a different pip value?
Brokers define the lot and the pip differently for some instruments, and for non-USD accounts the pip value depends on a live exchange rate. For forex majors with a USD account the $10 per standard lot figure is reliable; for gold, indices and crypto always use the contract specification of your broker.
What if the calculated lot size is smaller than my broker's minimum?
Then the trade cannot be taken at that risk and stop. Tighten the stop if the chart allows it, use a broker or account type with smaller lots, or skip the trade. Rounding the size up, or raising the risk percentage to fit the minimum, takes more risk than you planned.
Does a bigger lot size mean a better trade?
No. Lot size only scales both profit and loss. The same dollar risk with a wider stop means a smaller lot. A bigger lot on the same stop means a larger loss when the stop is hit. Size follows the risk you chose, not the other way round.
Size the trade, then place the stop well.
A lot size is only as good as the stop behind it. These indicators help you find where the stop belongs.
Guides that explain it
Pre-set for your instrument
Pip, point and tick values differ by market. These pages start from the right contract for each one.
Last updated November 2026. For education only. Not financial advice. Results depend on your inputs and cannot predict future performance.