Fibonacci Calculator
Key retracement and extension levels in one click.
Input a swing high and swing low. Get the 23.6%, 38.2%, 50%, 61.8%, and 78.6% retracement levels plus the 127.2%, 161.8%, 200%, and 261.8% extension levels. Works for uptrends and downtrends.
Where pullbacks commonly find support/resistance before continuing the trend.
Where trends commonly hit profit-taking targets beyond the original swing.
What it is
Fibonacci retracement measures how deep a pullback goes against the main trend, expressed as a percentage of the original move. Extensions project where price might go if the trend continues past the swing high (or low). These levels aren't magic — they're just the most-watched levels by institutional and retail traders, which is what gives them their self-fulfilling power.
When to use it
After identifying a clear swing high and swing low on your chart. Fibonacci is useful for: finding pullback entries during established trends, projecting take-profit targets, and spotting confluence with horizontal structure. It's most reliable when the levels line up with prior support/resistance — isolation Fib levels are weaker signals.
The formula
For an uptrend (retracement pulls DOWN from the high): Level = High − (Range × Fib %) where Range = High − Low For a downtrend (retracement pulls UP from the low): Level = Low + (Range × Fib %) For extensions (project beyond the swing): Uptrend extension = High + (Range × (Extension % − 1)) Downtrend extension = Low − (Range × (Extension % − 1)) Key retracement %: 23.6, 38.2, 50, 61.8, 78.6 Key extension %: 127.2, 161.8, 200, 261.8 The 61.8% retracement and 161.8% extension are the two most-watched levels — they show up in every institutional trading platform.
How to use it
- 1. Identify a clean swing on the higher timeframe
Look at the 4-hour or daily chart. Find a clear move where price went from an obvious low to an obvious high (or vice versa). Do not guess — the swing points should be visually obvious.
- 2. Enter the swing high and swing low
Use actual wick prices, not close prices. The extremes of the swing are what count — they define the range the market is retracing.
- 3. Pick direction
Uptrend if price made the high after the low (price moved up). Downtrend if price made the low after the high (price moved down). The calculator flips the math accordingly.
- 4. Look for confluence with structure
The best Fib levels line up with prior support/resistance, a prior swing low/high, or a moving average. Fib levels in the middle of nowhere are just numbers. Fib + structure = real level.
- 5. Use levels for entries, not signals
Fibonacci tells you where price might turn — it does not tell you it WILL turn. Always wait for price action confirmation at the level: a pin bar, engulfing candle, or a clean reaction off structure.
Common mistakes
- ✗Trading Fib levels in isolation. Without confluence (structure, trend, price action), Fib levels have roughly coin-flip reliability.
- ✗Using Fib on random swings. If the swing isn't a clean, obvious move, the levels you draw will be meaningless. Pick decisive swings only.
- ✗Putting entries exactly at a Fib level. Levels are zones, not lines. Expect 5-15 pips of slippage on either side — size your stops accordingly.
- ✗Ignoring the 50% level because it's 'not a real Fibonacci number.' It's not from the Fibonacci sequence but it's one of the most-watched retracements in trading. Use it.