Forex Lot Size Calculator
Convert a stop-loss distance in pips into standard, mini and micro lots for your account size and risk percentage.
Forex positions are sized in lots, and a forex lot size calculator exists because the increments are not intuitive: a standard lot is 100,000 units of the base currency, a mini lot is 10,000, and a micro lot is 1,000. Brokers usually accept fractional lots in 0.01 increments, so a position can be anything from a hundredth of a lot upwards.
Formula: lots = (balance × risk%) ÷ (stop in pips × pip value per lot)
Your figures
Choose Custom to enter your broker's own pip size and contract size.
Percentage of the balance to risk on this trade.
How far the stop sits from the entry, in pips.
Rate to convert the pair's quote currency into your account currency. Enter 1 if they are the same.
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
Lot size
0.20
standard lots
- Amount at risk
- US$50.00
- Rounded to broker increment (0.01)Rounded down so the risk never exceeds your target.
- 0.20 lots
- Risk at the rounded size
- US$50.00
- Mini lots (10,000 units)
- 2.00
- Micro lots (1,000 units)
- 20.00
- Units of base currency
- 20,000
- Pip value per standard lot
- US$10.00
What this means
Trading 0.20 standard lots of EUR/USD means a 25.0-pip loss costs US$50.00. Most brokers accept sizes in 0.01-lot steps, so the rounded figure is the one you can actually place.
- Rounding is always downward, so the position risks slightly less than the target rather than slightly more.
Lot size: 0.20
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Continue with these figures
About the Forex Lot Size calculation
This calculator converts a stop-loss distance measured in pips into how many lots to trade, given your account balance and the percentage you are willing to risk. It is the quicker route when you already think about stops in pips rather than in prices.
The forex lot calculator also rounds the result down to the 0.01 increment brokers accept and shows what that rounding does to your actual risk, which is usually a small reduction rather than an increase.
Forex Lot Size formula
risk amount = balance × (risk % ÷ 100)
pip value per standard lot = pip size × 100,000 × quote-to-account rate
lots = risk amount ÷ (stop in pips × pip value per standard lot)
rounded lots = floor(lots × 100) ÷ 100- pip size
- 0.0001 for most pairs; 0.01 for JPY-quoted pairs.
- stop in pips
- Distance from entry to stop, measured in pips.
- floor
- Round down. Rounding up would risk more than budgeted.
Working in lots rather than units keeps the numbers small. Pip value per standard lot is a constant for a given pair and conversion rate — $10 for most USD-quoted pairs — so the division is straightforward once that is known.
The rounding step matters more than it looks. At small account sizes the exact figure is often something like 0.037 lots, and the difference between 0.03 and 0.04 is more than 30% of the position. Rounding down is the conservative choice because it can only reduce the risk taken.
Forex Lot Size: a worked example
A $5,000 account risking 1% on a EUR/USD trade with a 25-pip stop. The account is in US dollars, which is the quote currency, so no conversion is needed.
- Risk amount5,000 × 1% = $50
- Pip value per standard lot0.0001 × 100,000 × 1 = $10
- Lots50 ÷ (25 × 10) = 0.20
- Rounded to 0.010.20 lots
- Risk at that size0.20 × 25 × 10 = $50.00
0.20 lots — two mini lots, or 20,000 units of euro. The stop-out costs exactly the $50 budgeted.
How to use the Forex Lot Size calculator
- Select the pair so the calculator uses the right pip size.
- Enter your account balance and the percentage you are prepared to risk on this trade.
- Enter the stop-loss distance in pips. If you know the prices instead, use the position size calculator, which derives the pip distance for you.
- Set the quote-to-account conversion rate, or leave it at 1 if the quote currency matches your account currency.
- Use the rounded lot figure when placing the order — it is the size your broker will accept.
Limitations of the Forex Lot Size calculator
Every calculation makes assumptions. These are the ones that matter here.
- Brokers set their own minimum and maximum position sizes, and some do not offer micro lots at all.
- Excludes spread and commission, which increase the real cost of a losing trade.
- Assumes the stop fills at the stop price, which gaps and slippage can prevent.
Frequently asked questions about Forex Lot Size
What is the difference between a lot and a unit?
A unit is one unit of the base currency, and standard, mini and micro lots are simply fixed bundles of them: 100,000, 10,000 and 1,000 units respectively. Lots exist purely as a convenient shorthand — trading 0.5 lots and trading 50,000 units are the same thing.
Why round the lot size down rather than to the nearest increment?
Rounding up increases the risk beyond what you budgeted. Rounding down reduces it slightly. Over many trades the difference is small, but only one direction can breach the limit you set.
My calculated lot size is below 0.01. What does that mean?
The stop distance is too wide, or the risk budget too small, for the smallest position your broker accepts. Either the trade cannot be taken at that risk level, or the stop needs to be tighter.
Does this work for gold, indices or other CFDs?
Not directly. Contract sizes and tick values for those instruments differ from the forex lot convention. The general position size calculator, which works from prices rather than pips, is the better fit.
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