Trailing Stop Loss Calculator
Calculate a dynamic stop price for a long or short position by percentage, fixed price distance or ATR. See the protected result, giveback and whether the stop has already been reached.
Trailing stop analysis
| Setting | Stop price | Gap to stop | Net P&L at stop | Status now |
|---|
Trailing stop formulas
For a long position, the stop follows the highest price recorded since entry. For a short position, it follows the lowest price:
Long percentage stop = highest price × (1 − trailing percentage)
Short percentage stop = lowest price × (1 + trailing percentage)
With a fixed distance, subtract the distance from the long reference high or add it to the short reference low. With ATR, the distance is ATR × multiplier. The calculator never moves the reference price backward.
Net P&L at stop = directional price change × quantity − estimated fees
Verified examples
| Position and method | Stop | Net P&L at stop | Return at stop |
|---|---|---|---|
| Long: entry US$100, current US$120, high US$125, 5% trail, 100 shares, US$4 fees | US$118.75 | US$1,871.00 | 18.7100% |
| Short: entry US$100, current US$85, low US$80, 10% trail, 100 shares, US$4 fees | US$88.00 | US$1,196.00 | 11.9600% |
| Long: entry US$50, current US$58, high US$60, ATR US$2 × 2.5, 200 shares, US$10 fees | US$55.00 | US$990.00 | 9.9000% |
How to use this trailing stop calculator
- Select long or short and choose a percentage, fixed-distance or ATR method.
- Enter entry price, current price and the best price reached since entry: the highest price for a long or the lowest for a short.
- Enter the trail setting, quantity and estimated entry-plus-exit fees.
- Compare the chosen stop with tighter and wider settings in the sensitivity table. A tighter trail protects more of the move but is easier to trigger.
Trailing stop versus stop loss and stop limit
A fixed stop loss stays at one trigger price. A trailing stop moves only when the position reaches a new favorable extreme and does not move back when price reverses. A trailing stop market order normally becomes a market order after the trigger, so its fill can differ from the stop price. A trailing stop-limit order adds a limit price and may not execute at all in a fast market.
Percentage, fixed-distance and ATR methods
A percentage trail scales with price and is easy to compare across assets. A fixed distance is appropriate when the price unit itself is meaningful. ATR adapts the distance to recent volatility, but the ATR value must come from a consistent chart interval and lookback; this calculator does not download market data.
Limits and assumptions
- Prices, fixed distance and ATR accept values above zero through 1,000,000,000 with up to six decimal places. Quantity uses the same range; estimated fees may range from zero through 1,000,000,000,000.
- The trailing percentage must be greater than 0% and less than 100%. The ATR multiplier must be greater than zero and no more than 100.
- For a long position, the reference high must be at least the entry and current prices. For a short position, the reference low must not exceed either price.
- A long stop must remain above zero. Sensitivity rows that would create a nonpositive price are shown as unavailable.
- Scientific notation, thousands separators and decimal commas are not supported. Use a decimal point and no more than six decimal places.
- The result assumes the order could fill at the calculated stop. Real fills can be worse because of gaps, slippage, liquidity, trading halts or broker order rules.
- Taxes, borrowing costs, margin interest, partial fills and changing quantity are excluded. Results are educational, not investment advice.
A triggered result means the entered current price is already at or beyond the calculated stop. It does not confirm that an order was placed or filled.
Frequently asked questions
Does a trailing stop move down on a long position?
No. Its reference high can only rise. When price falls, the stop remains at the level calculated from the highest recorded price.
What is a good trailing stop percentage?
There is no universal percentage. A suitable distance depends on volatility, holding period, liquidity and the loss the trader can accept. Use the sensitivity table rather than treating one percentage as a guarantee.
Can I use ATR for a short position?
Yes. The calculator adds ATR × multiplier to the lowest price reached since entry. Keep ATR frequency and lookback consistent with the trading plan.
Related calculators
- Position Size Calculator — size a trade from account risk and an initial stop.
- Profit Factor Calculator — evaluate completed-trade performance and expectancy.
- Risk of Ruin Calculator — estimate survival probability under a fixed-risk model.
- Futures Profit Calculator — calculate contract P&L from ticks or points.