Trailing Stop Price Calculator

How it is calculated

The tool is for a long position and trails by a percentage only. You enter the entry price, the highest price reached since entry (the peak) and the trail percent. It computes stop = peak × (1 − trail% / 100), the distance trail amount = peak − stop, and the gain locked in if the stop is hit, gain = stop − entry, also as a percentage of the entry. Entry and peak must be above zero, the trail must be above 0 and below 100, and a peak below the entry price gives no result because the peak is measured since entry. A negative locked gain means the stop still sits below your entry, so a stop-out would be a loss (at a peak equal to the entry, a 10 % trail locks in −10 %). The stop only rises when the peak rises, so update the peak yourself. Gaps and slippage can fill the order below the stop.

Common mistakes

• Entering the current price instead of the highest price since entry. The stop then sits too low as soon as the price pulls back, and a current price below your entry gives no result.
• Recalculating the stop from a lower peak after a pullback. A trailing stop never moves down, so keep the highest peak.
• Choosing a trail so tight that normal daily swings trigger it, or so wide that little gain is locked in.
• Expecting the sale at exactly the stop price. In fast markets or after a gap the order can fill lower.
• Entering the trail as a money amount such as 5 dollars. The field is a percentage, so 5 means 5 %.