Tested tool guide
Tested browser tools
Checked August 16, 2026
What Forex Position Size Calculator does, with a checked example
This calculator translates a trading-risk limit into a forex position size. Enter the account balance, the percentage of that balance you are prepared to risk, the stop-loss distance in pips, and the pair's pip value for one standard lot. The calculator converts the percentage into money at risk, then divides it by the loss that one lot would incur at the stop. The common mistake is entering a pip value for the wrong lot size or account currency.
Worked example
A concrete input and expected output from the current implementation.
Input
Account balance: USD 10,000
Risk: 1%
Stop loss: 25 pips
Pip value per standard lot: USD 10 per pip
->
Expected output
0.40 standard lots
The risk allowance is USD 10,000 x 1% = USD 100. One standard lot would lose 25 x USD 10 = USD 250 at the stop, so the position size is USD 100 / USD 250 = 0.40 lots.