Fibonacci Retracement & Extension Calculator
Calculate Fibonacci retracement levels (23.6%, 38.2%, 50%, 61.8%, 78.6%, 100%) and extension levels (100%, 161.8%, 261.8%, 423.6%) from swing high and swing low. Works for stocks, forex, and crypto. All calculations run 100% in your browser — no data is sent anywhere.
Retracement Mode
Enter swing high and swing low, pick the trend direction, then see the 6-level table with prices.
The results above are pure mathematical computations of Fibonacci ratios against the swing you entered — not buy or sell recommendations, and no guarantee price will react at those levels.
Extension Mode
Enter the initial swing (low → high) and the retrace point, then see the projected 100%, 161.8%, 261.8%, and 423.6% levels.
Extension levels are geometric projections, not price targets guaranteed to be hit. In real markets, price often fails to reach projected levels or overshoots them far.
Custom Ratio Mode
Compute the price for one free ratio between 0 and 4 (e.g. 0.786 for 78.6% or 1.272 for harmonic patterns).
Custom ratios are computed with the same formula as retracement. Non-standard ratio numbers carry no special technical meaning — understand the basics first before using them.
Worked Example
Retracement (uptrend): swing high 100, swing low 50. Range = 50. 61.8% level = 100 − 0.618 × 50 = 69.1; 38.2% level = 100 − 0.382 × 50 = 80.9.
Extension (uptrend): swing 100 → 150 (range 50), retrace point 120. 161.8% level = 120 + 1.618 × 50 = 200.9.
The example above was recomputed directly by this page’s calculator engine.
Frequently Asked Questions (FAQ)
What is Fibonacci retracement?
Fibonacci retracement is a technical analysis technique that computes price levels between swing high and swing low using ratios derived from the Fibonacci sequence: 23.6%, 38.2%, 50%, 61.8%, 78.6%, and 100%. Market participants use these levels as reference areas to watch price reactions. It is an analytical aid, not a prediction — no level guarantees price will reverse.
How do you calculate Fibonacci retracement levels?
The formula is simple. For an uptrend: level = swing high − ratio × (swing high − swing low). For a downtrend: level = swing low + ratio × (swing high − swing low). Example: swing high 100 and swing low 50 in an uptrend give a 61.8% level = 69.1 and a 38.2% level = 80.9.
What is Fibonacci extension?
Fibonacci extension projects price beyond the initial swing using ratios of 100%, 161.8%, 261.8%, and 423.6% of the swing length. Uptrend formula: level = retrace point + ratio × (swing high − swing low); downtrend: level = retrace point − ratio × (swing high − swing low). Example: a swing from 100 to 150 with retrace point 120 gives a 161.8% level = 200.9.
Why is the 50% level used even though it is not a Fibonacci ratio?
Correct — 50% is neither a Fibonacci-derived ratio nor the golden ratio. The level is still widely used because the midpoint of a range often acts as a psychologically significant price-reaction area. This calculator lists it as-is as a psychological level, not a pure Fibonacci ratio.
Can Fibonacci levels predict where price will move?
No. Fibonacci levels help map areas that many market participants watch; they are not a forecast. Price can break through any level. Never make buy or sell decisions based on a single indicator. This calculator is educational and not investment advice.
Where do the 61.8% and 38.2% numbers come from?
Both derive from the golden ratio (phi ≈ 1.618) of the Fibonacci sequence: 61.8% ≈ 1/phi; 38.2% ≈ (1/phi)²; 23.6% ≈ (1/phi)³; 78.6% ≈ the square root of 0.618; while 161.8% = phi, 261.8% = phi², and 423.6% = phi³. The values this calculator uses are standard industry roundings.
What is the difference between uptrend and downtrend calculations?
In an uptrend, levels are measured back from the swing high: level = high − ratio × range, so the 0% level sits at the high and 100% at the low. In a downtrend it is reversed: level = low + ratio × range, so the 0% level sits at the low and 100% at the high. Pick the direction matching the swing structure you are analyzing.
How do I use this calculator?
First, pick a mode: Retracement, Extension, or Custom Ratio. Second, enter swing high and swing low (for extension, add the retrace point). Third, choose the uptrend or downtrend direction. Optional: enter the current price to see each level’s distance from the current price. The result is a table of levels with their prices — use it as analytical input, not as buy or sell signals.