How to use this calculator
- Choose the pair and account currency, then enter your account balance.
- Set a percentage or fixed cash-risk budget and a stop distance in pips.
- Enter any required conversion quote. Confirm units per lot and the broker’s lot increment before reading the rounded size.
Forex position sizing calculator formula
Percentage risk is balance × risk percentage ÷ 100. A fixed cash amount is used directly. The calculator divides that budget by the loss associated with one lot moving the entered stop distance.
The adverse pip value uses the conversion side needed to cover a quote-currency loss. It is not a universal USD 10 constant. The suggested trade lots are rounded down, so the modelled stop loss does not exceed the budget just because of lot rounding.
A USD 100 risk-budget example
Assume a USD 10,000 balance, 1% chosen risk, EUR/USD, a 25-pip stop and 100,000 units per lot. The cash budget is USD 100 and the pip value per full lot is USD 10. Dividing 100 by (25 × 10) gives 0.40 lots.
At a 0.01-lot increment, this example needs no further reduction. Its 40,000 base units equal four mini lots or 40 micro lots. Those are equivalent units, not three extra positions to open.
| Measure | Example value |
|---|---|
| Chosen cash risk | USD 100 |
| Standard lots | 0.40 |
| Mini-lot equivalents | 4 |
| Micro-lot equivalents | 40 |
| Base-currency units | 40,000 EUR |
| Adverse pip value for the position | USD 4 |
Check JPY pips, contract size and lot steps
For JPY-quoted pairs, the pip size is 0.01. Other supported pairs use 0.0001. Entering pipettes as full pips changes the estimated size by a factor of ten, so confirm the convention shown in your terminal.
The default contract is 100,000 base units per trade lot. Change it only to match the actual broker specification. Standard, mini and micro equivalents always mean 100,000, 10,000 and 1,000 base units, even if you select a different trade-lot contract.
A size below one selected lot increment returns zero and a warning. A mathematically calculated size is not an instruction to change the broker’s minimum or increase the risk budget.
Planned risk and actual loss can differ
The estimate excludes commission, swaps and slippage. A stop order can fill beyond the requested price during gaps or fast markets. Margin requirements, maximum position limits and existing exposure also need checking before an order.
Test exit-price scenarios with the forex trading profit calculator, including known round-trip costs.
Review our funded-account risk-rule guide if a programme also has daily or total loss restrictions. A per-trade calculation does not track those limits.
The CFTC’s forex guidance explains why leverage and provider checks matter. The percentage you choose is your assumption, not a recommendation from this tool.
Frequently asked questions
What percentage should I risk per trade?
There is no universally suitable percentage. Enter your own budget after considering loss capacity, open positions, costs and account rules. This calculator does not recommend a risk level.
Why is the lot size rounded down?
Rounding up could exceed the entered risk budget. The tool rounds down to the selected lot increment; confirm that increment and any minimum size with your broker.
Does the stop loss cap the amount I can lose?
No. Gaps, slippage and fees can make the final loss larger. The estimated stop loss also does not confirm that your account has enough margin for the position.