This Lot size calculator allows you to calculate the optimal trading lot for Forex according to your risk as % of deposit or amount of money. Calculator can work with the major currency pairs, cross rates, as well as metals. You need to fill in a form according to your preferences, and then click the "Calculate" button. Field with the current quote Ask (required for some instruments) is filled in automatically at the current market situation. You can also manually adjust it if necessary.
An example of how to calculate: for example, your trading system gave the signal to open trade with a stop loss of 50 points. Your deposit is $500 and you are willing to risk 3% of the deposit in this transaction. In the "Deposit" write 500, in the "Risk" 3 and in the "Stop Loss" - 50. As the result you'll see that your risk is $15, and your trading lot - 0.03.