Trailing Stop Price Calculator
Set a percentage trailing stop and see the exact trigger price, the gain it locks in, and how much room it leaves below the recent high.
How it works
Stop price = highest price × (1 − trail% ÷ 100) · Locked P/L per share = stop − entry
A trailing stop follows the highest price the position reaches and only ever moves up, never down. As the stock climbs, the stop ratchets higher, converting more of the paper gain into a protected floor. Choosing the trail width is the trade-off: too tight and normal pullbacks stop you out; too wide and you give back a large slice before the stop fires.
Worked example
You buy at $100 and the stock runs to a $120 high. A 10% trailing stop sits 10% below that high, at $108. If price falls to $108 you exit with $8 per share locked in — an $800 gain on 100 shares — instead of watching the whole run evaporate.
Frequently asked questions
Does the trailing stop move if the price drops?
No. It only ratchets upward with each new high and then holds. A trailing stop that moved down with the price would defeat its purpose of protecting gains.
Percentage or dollar trailing stop — which is better?
Percentage stops adapt to the stock’s price level, which is handy across positions of different sizes. Dollar or ATR-based stops adapt to the stock’s actual volatility. Many traders prefer volatility-based trailing stops so the width matches how much the stock normally moves.
How wide should the trail be?
Wide enough to survive the stock’s ordinary daily swings but tight enough to protect meaningful profit. Basing the width on a multiple of Average True Range ties it to real volatility rather than a round number.
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Educational estimate, not investment advice. Trading involves risk of loss.