Identify the price levels traders watch for pullbacks and targets. Enter your swing high, swing low, and trend direction to instantly compute the 23.6%, 38.2%, 50%, 61.8%, 78.6% retracements and the 127.2%, 161.8%, 261.8% extensions.
Fibonacci retracement levels mark potential pullback points within a price move, calculated as percentages of the swing's total range subtracted back from the extreme. The calculator takes the range (swing high minus swing low) and, for an uptrend, subtracts each Fibonacci ratio of that range from the high — for a downtrend, it adds each ratio back onto the low.
Extension levels work the same way but project beyond the original swing, giving traders potential target zones if price continues past the prior high or low. They're calculated as the same ratios applied outward from the opposite end of the swing, rather than back into it.
The specific percentages — 23.6%, 38.2%, 50%, 61.8%, 78.6% for retracements and 127.2%, 161.8%, 261.8% for extensions — come from ratios in the Fibonacci sequence, and are widely watched by other market participants, which is part of why they can act as self-fulfilling areas of support, resistance, or reaction.
Worked example: for an uptrend swing from a low of 1.0800 to a high of 1.1200 (a 400-pip range), the 61.8% retracement sits at 1.09528 — a common pullback entry zone — while the 50% level sits at exactly 1.1000. If the trend continues past the prior high, the 161.8% extension projects a target at 1.14472.
They're horizontal lines marking percentages of a prior price move (23.6%, 38.2%, 50%, 61.8%, 78.6%) where a pullback might pause or reverse before the trend resumes. Traders use them to plan entries during a retracement in an existing trend.
The 61.8% level (the 'golden ratio') and the 50% level are the most widely watched, often treated as the deepest pullback a healthy trend should retrace before a break of structure suggests the trend may be over.
Retracement levels sit inside the original price swing and mark potential pullback points. Extension levels project beyond the original swing and mark potential targets if the trend continues past its previous high or low.
Use a clearly defined, significant swing on your chart — typically the most recent major high and low that formed the trend you're analysing. Different swing choices produce different levels, so consistency in how you pick swings matters more than any single 'correct' choice.
They're used across forex, stocks, crypto, and indices, on timeframes from minutes to months, because they reflect trader psychology and crowd behaviour rather than any property specific to one asset class — though like all technical tools, they work best combined with other confirmation.