How to Use the Forex Lot Size Calculator
- Enter your account balance.
- Enter the percentage of the account you will risk on this trade.
- Enter the stop loss distance in pips.
- Choose the pair type: USD quote, JPY pairs, other quotes or gold.
- Read the lot size, units, pip value and actual risk after rounding.
Enter your account balance, the percentage of it you are willing to lose if the trade hits its stop, and the distance to the stop loss in pips. Many traders risk 1% or 2% per trade, but the right figure is your own decision. Then choose the pair type, because the value of one pip depends on the quote currency, the second currency in the pair.
For JPY pairs and other non-USD quote currencies, enter the current exchange rate so the pip value can be converted to US dollars. For gold, choose how your broker defines a pip. If your account is not in US dollars, enter how many units of your account currency one dollar buys. The result shows the position size in standard lots, rounded down to 0.01, plus units, mini and micro lots, the pip value and the money at risk.
Lot Size and Pip Value Formulas
lots = amount at risk ÷ (stop loss pips × pip value per lot)
XXX/USD: pip value = 100,000 × 0.0001 = $10 per lot
JPY pairs: 100,000 × 0.01 ÷ USD/JPY rate
XAU/USD: 100 oz × pip size ($0.10 = $10 per lot)
For a pair quoted in US dollars, one pip (0.0001) on a 100,000-unit standard lot is always $10. For JPY pairs a pip is 0.01, worth 1,000 yen per lot, which is converted to dollars at the USD/JPY rate. For other quote currencies the pip is worth 10 units of that currency per lot, converted at the USD/quote rate.
Gold is quoted per troy ounce with 100 ounces in a standard lot. Brokers disagree on what a pip is for gold: many treat $0.10 as one pip, others $0.01, so check your platform before you trade.
Worked Example
With a $10,000 account, 1% risk and a 25-pip stop on EUR/USD, you can lose $100. Each standard lot moves $10 per pip, so the stop costs $250 per lot and the position is 100 ÷ 250 = 0.40 lots, or 40,000 units, worth $4.00 a pip. On USD/JPY at 150.00 a pip is worth $6.67 per lot, so the same risk allows 0.60 lots.
On gold with a 50-pip ($5.00) stop, a lot moves $10 per pip, so 1% risk allows 0.20 lots, which is 20 ounces. Risking 2% on USD/CAD at 1.3700 with a 40-pip stop gives an exact size of 0.6850 lots, rounded down to 0.68, for an actual risk of $198.54.
| Pair type | Pip size | Pip value, standard lot | Mini lot | Micro lot |
|---|---|---|---|---|
| EUR/USD and other XXX/USD | 0.0001 | $10.00 | $1.00 | $0.10 |
| USD/JPY at 150.00 | 0.01 | $6.67 | $0.67 | $0.07 |
| USD/CAD at 1.3700 | 0.0001 | $7.30 | $0.73 | $0.07 |
| XAU/USD, $0.10 pip | 0.10 | $10.00 | $1.00 | $0.10 |
A mini lot is 10,000 units and a micro lot 1,000 units; for gold they are 10 oz and 1 oz.
Risk Management Tips
- Set the stop loss where the trade idea is wrong, then size the position to fit it. Do not move the stop to fit a size you want.
- Recalculate before every trade. The pip value of JPY and other non-USD pairs changes with the exchange rate.
- Allow for the spread and commission, which add to the real loss if the stop is hit.
- Gaps over weekends or news can push the fill past your stop, so the actual loss can be larger.
- Check your broker's lot step. Some only allow 0.1 lots, which means rounding down further.
Assumptions and Limits
The calculator uses standard lots of 100,000 units for currencies and 100 ounces for gold, and pip sizes of 0.0001, 0.01 for JPY pairs, and your chosen gold pip. Cross-pair conversions use the rate you enter. Leverage and margin requirements are not checked. Trading forex and gold on margin carries a high risk of loss. This is a calculation tool, not trading advice.
Frequently asked questions
How do I calculate lot size in forex?
Multiply your balance by the risk percentage to get the amount you can lose. Divide that by the stop loss in pips times the pip value per lot. The result is the lot size.
What is the pip value of a standard lot?
For pairs quoted in US dollars, such as EUR/USD, it is $10 per pip. For other pairs it depends on the exchange rate, for example about $6.67 for USD/JPY at 150.00.
How is the lot size for gold XAUUSD calculated?
One standard lot of gold is 100 ounces. If your broker treats $0.10 as one pip, each pip is worth $10 per lot. Divide your risk by stop pips times that value.
What is the difference between standard, mini and micro lots?
A standard lot is 100,000 units of the base currency, a mini lot is 10,000 units and a micro lot is 1,000 units. In lot terms they are 1.00, 0.10 and 0.01.
How much should I risk per trade?
Many traders limit risk to about 1% to 2% of the account per trade so a losing streak does not wipe them out. The right amount depends on your strategy and tolerance for losses.
Why is my position size rounded down?
Brokers trade in steps, usually 0.01 lots. Rounding down keeps the loss at the stop at or below your planned risk. The calculator also shows the exact size before rounding.