Position size calculator
Work out how many shares or contracts to buy from your capital, risk per trade (%) and stop.
How to useHow many shares to buy with the right risk
Educational tool, not investment advice.
Available in: 
Position size calculator: what it is for
Enter your capital, the percentage you accept to lose on the trade, the entry price and the stop price. The calculator shows the number of shares (rounded to the lot size), the position value, the share of capital used and the real loss if the stop is hit.
Educational tool: the calculations are estimates and not investment advice.
How to use
- Enter capital and risk per trade.
- Enter entry and stop.
- See the ideal quantity.
When to use it
- Control risk in day trading and swing trading.
- Standardize the maximum loss per trade.
- Build the trade plan before entering.
Frequently asked questions
How is position size calculated?
Quantity = (capital × risk %) ÷ (entry price − stop price). If the stop is hit, you lose only the percentage of capital you set.
What risk per trade is common?
Many traders risk between 0.5% and 2% of capital per trade. The lower the risk, the more losses in a row you can absorb.
Does it work for short selling?
Yes. Put the stop above the entry; the calculator uses the absolute distance between the two prices.
Is it really free?
Yes, 100% free. No sign-up, no subscription and no usage limits. All Tools123 are free.