Trailing stop calculator: see the gain a trailing stop locks in

A trailing stop sits a set percentage below the highest price reached and only moves up. Enter your entry price, the high since entry and a trail percentage to see where the stop is and how much gain it protects.

Formula

Trailing stop = Highest price since entry × (1 − Trail %). Locked-in gain = Trailing stop − Entry price.

What you need

Entry price
Highest price since entry
Trail percentage
Number of shares

Worked example

You bought at $80 and the stock has reached $110. A 10% trail puts the stop at $99, locking in $19 per share, 23.8% on your entry, if it triggers there.

Why trail instead of fixing a stop

A fixed stop protects the same level forever. A trailing stop keeps raising the floor as the position gains, so more of the open profit is protected over time without capping the upside.

Choosing the trail percentage

A trail that is tight relative to the stock’s normal movement will trigger on routine pullbacks. Compare the trail distance with the stock’s ATR, or use an ATR-based trail such as the Chandelier Exit for a distance that adapts to volatility.

Gaps and fills

When triggered, a stop order becomes a market order. If the price gaps below the stop, the fill can be lower than the level shown here, so the locked-in gain is an estimate, not a guarantee.

Common questions

How is a trailing stop calculated?

Take the highest price reached since you started trailing and subtract the trail distance. With a percentage trail, multiply the high by one minus the trail percentage.

Can a trailing stop lock in a profit?

Yes. Once the trailing level rises above your entry price, a trigger at that level would close the position at a gain.

Profit Lock

Profit Lock helps investors turn an open position into a clear exit plan. It compares several stop models, grades the quality of each level, and shows the risk before you make a manual decision.

Explore Profit Lock