0.0%
$100.00
Fibonacci Calculator
Calculate Fibonacci retracement and extension levels for a price swing.
61.8% Retracement
$69.10
23.6%
$88.20
38.2%
$80.90
50.0%
$75.00
61.8%
$69.10
78.6%
$60.70
100.0%
$50.00
How to use the Fibonacci Calculator
The Fibonacci Calculator is free and runs entirely in your browser — no sign-up, and nothing you enter leaves your device. It opens pre-filled with a realistic example, so you can see how it works before replacing any figure with your own; the results update as you type. Press Calculate to refresh the result panel, or Reset to return to the example.
The inputs it asks for:
- Swing High — a dollar amount.
- Swing Low — a dollar amount.
- Trend Direction — choose one — Uptrend (retracement down), Downtrend (retracement up).
The formula
It marks the classic Fibonacci retracement levels across a price swing. Each level is a fraction of the high-to-low range measured back from the extreme, in the direction a pullback would move:
Level price (uptrend) = High − (High − Low) × ratio
Ratios: 23.6%, 38.2%, 50%, 61.8%, 78.6%- High, Low
- the swing's extremes
- ratio
- the Fibonacci retracement fraction
The key ratios (notably 61.8%, the "golden ratio") come from the Fibonacci sequence; 50% is included by convention though it isn't a Fibonacci number. These are levels some traders watch for a pullback to pause or reverse — a charting aid, not a prediction.
Worked example
Using the example values — Swing High $100.00, Swing Low $50.00, Trend Direction Uptrend (retracement down) — the Fibonacci Calculator returns a 61.8% Retracement of $69.10. It also reports 0.0% ($100.00), 23.6% ($88.20), 38.2% ($80.90).
Prefer your own numbers? Change any field above and this recomputes instantly.
Key terms
- Retracement
- A temporary counter-move within a larger trend.
- Fibonacci ratios
- 23.6%, 38.2%, 61.8% (and 78.6%) — derived from the Fibonacci sequence.
- Golden ratio
- ~61.8%, the most watched Fibonacci retracement level.
- Swing high / low
- The extremes of the price move being measured.
Frequently asked questions
Where do the ratios come from?
From the Fibonacci sequence: dividing terms gives ~61.8%, ~38.2%, and so on. 50% isn't a true Fibonacci ratio but is included by long-standing convention.
Do prices really respect these levels?
Sometimes price pauses or reverses near them, but there's no guarantee. Their influence is partly self-fulfilling because so many traders plot the same lines.
Uptrend vs downtrend — what changes?
The direction the retracement is measured. In an uptrend levels are measured down from the high; in a downtrend, up from the low.