Stop-Loss Calculator
Convert a selected percentage, ATR multiple, or risk budget into a stop price with visible formula substitution.
Turn a risk rule into a stop price
Advanced settings
Choose the right tool
Stop price or position size?
Stop-Loss Calculator
You know the position or stop rule. Calculate the stop price.
Position Size Calculator
You know the stop and maximum risk. Calculate the share count.
Calculate a smaller position →Worked example
Convert stop distance into planned stock risk
For a long position entered at $80, a 5% stop distance gives a $76 stop price and $4 planned risk per share. With 25 shares, planned risk is $100 before costs. If execution occurs at $75.50, the loss becomes $112.50 before fees. The trigger price and the eventual fill price can differ.
Continue with the related guides
Frequently asked questions
How do I calculate a percentage stop-loss price?
For a long position, multiply entry price by one minus the stop percentage. For a short position, multiply entry price by one plus the stop percentage.
How do stop price and position size work together?
Choose the price that invalidates the trade idea, calculate the distance from entry, then divide the dollar risk budget by that per-share distance. Position sizing translates a stop into an exposure limit.
Can the calculator choose the best stop for a stock?
No. It converts a percentage, ATR multiple or risk budget you specify. It does not identify support, forecast price movements or guarantee execution.
How to use
From inputs to a result you can review
- Choose Percentage, ATR, or Risk Budget.
- Select long or short and enter the planned entry.
- Add a position size to calculate total planned risk.
- Optionally include target price, fees, and estimated slippage.
- Review both the planned stop and execution-risk estimate.
Known limitations
What this calculation does not know
- ATR describes recent price range; it does not predict future volatility.
- A stop order may execute beyond the selected price.
- Technical support, liquidity, and instrument-specific rules are not assessed.
- The output is a conversion of your rule, not an optimal-stop recommendation.
Educational calculation only. This is not personalized investment, trading, or tax advice.
Read the guide
Position size vs stop-loss: which comes first?
Connect stop distance, account risk, slippage, and a defensible position size.
Read the guide →Method version 1.0
Calculation logic reviewed against the published methodology and automated test cases. Last updated August 5, 2026.