Position sizing means deciding how much of your balance to risk on one trade before the trade is placed. This calculator turns a risk percentage into a stake and shows how the balance shrinks after a run of losses. It is a planning aid and does not recommend any percentage.
Position Size Calculator
Stake = balance × risk %. The loss-streak figures assume each stake is the same percentage of the shrinking balance. A binary option risks the whole stake on every trade.
How to Use This Calculator
- Enter your current account balance.
- Enter the percentage of the balance you are willing to risk on one trade.
- Read the stake and the balance after five and ten losses in a row.
The Maths Behind It
The stake is the balance multiplied by the risk percentage. Because each stake is a share of the shrinking balance, a streak of n losses leaves the balance multiplied by (1 minus the risk fraction) to the power n. Smaller percentages shrink the balance more slowly during a bad run, which is the main reason many traders choose small fixed percentages.
Limits
This tool uses only the figures you enter. It does not know your broker, your fees or your market, and its output is not advice or a prediction. Test any strategy on a demo account first, and read your platform's own terms.
Frequently Asked Questions
What percentage should I risk?
That is your decision and depends on your tolerance for a losing run. The calculator shows the effect of different choices; it does not pick one.
Does a binary option risk more than the stake?
In a standard fixed-return binary option the maximum loss is the stake, but check the terms of the product you use.
Should the stake change after every trade?
Only if your written plan says so. Changing stake sizes after wins or losses is a common source of mistakes.