Fib Retracement Calculator

Enter a swing high and a swing low and this calculator returns the Fibonacci retracement levels inside that move for an uptrend or a downtrend, plus a separate Extensions mode that projects targets beyond the swing. It adds two things most quick tools leave out: custom levels you define yourself, and a price ladder chart drawn from your own numbers, with the decimal precision under your control.

Quick Answer

How to use the Fib retracement calculator

Pick the mode that matches your swing, enter the two swing prices, and click Calculate. The results stay hidden until you calculate, and the ladder chart redraws from the same numbers.

1. Choose the mode: Uptrend Retracement if price climbed from the low to the high, Downtrend Retracement if it fell, or Extensions if you want targets beyond the swing. The labels on the price fields change to show which end is Point A and which is Point B.
2. Enter the swing high and swing low: use the actual extreme prices of one clean move, not the whole chart history. The high must be greater than the low, and both must be above zero, or the tool stops with a message naming the problem.
3. Set decimal places: 2 is right for most stocks and indices. Forex pairs and cheap crypto often need 4 or more. Be aware that entering 0 still displays 2 decimals; that quirk is documented below rather than hidden.
4. Add a custom level if you use one: type a percentage such as 45 or 65, click Add Level, then Calculate. Custom levels join the standard set in the results. In the two retracement modes only custom levels up to 100% are used; in Extensions mode every custom level is used.
5. In Extensions mode, enter the current price: it only selects the direction. If the current price sits below the swing low, levels project downward, measured from the swing high; otherwise they project upward, measured from the swing low.

Copy Results puts the full level list on your clipboard in the same format the tool has always produced, ready to paste into a trading journal or platform notes. Reset restores the $100 to $200 worked example and clears any custom levels.

The three formulas: uptrend, downtrend and extension

Every mode starts from the same range, Range = High − Low, and multiplies it by each ratio. What changes is the anchor: the high in an uptrend, the low in a downtrend, and the swing start in Extensions mode.

The ratios themselves come from the Fibonacci sequence, where each number is the sum of the two before it: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34. Dividing a number by the next one gives 0.618, the golden ratio tracked by the Britannica’s article on Fibonacci numbers at the University of St Andrews; dividing by the one two places ahead gives 0.382, and the square root of 0.618 gives 0.786. The retracement set built into the tool is 0%, 23.6%, 38.2%, 50%, 61.8%, 78.6% and 100%, and the extension set is 127.2%, 138.2%, 150%, 161.8%, 200%, 261.8% and 423.6%.

Worked example: a $100 to $200 uptrend, level by level

The range is $200 − $100 = $100, so each level is the high minus that percentage of $100. The table below is the exact output of the pre-filled calculator, including the two rows the tool calls out by name.

Read as a ladder, the same seven prices look like this. Bar length is the price itself, which is the fastest way to see how unevenly the levels are spaced: the gap from 0% to 23.6% is $23.60, while the gap from 78.6% to 100% is only $21.40 on a $100 range, and the middle levels bunch tighter than most beginners expect.

Run the same swing as a downtrend and the prices mirror: 0% sits at the low ($100.00), 38.2% is $138.20, 61.8% is $161.80 and 100% is the high ($200.00). Nothing about the swing changed; only the anchor did. That mirror is the single most common beginner mistake with this tool, picking the uptrend tab for a falling move and then reading resistance levels as support. If you later sell into one of these levels, the stock sell calculator works out what that exit actually returns after the trade.

Extensions here: read this before you trade them

Extensions mode projects seven levels beyond the swing: 127.2%, 138.2%, 150%, 161.8%, 200%, 261.8% and 423.6%. With the worked swing and a current price of $250 (above the high), they come out at $227.20, $238.20, $250.00, $261.80, $300.00, $361.80 and $523.60.

Here is the part other pages leave out. This tool computes an upward extension as Low + (Range × Ratio): the ratio is measured from the swing low, where the move started. That is the same price as High + (Range × (Ratio − 1)), and it is the anchoring most charting packages and extension tools use, so their 161.8% target for the same swing also sits at $261.80. True three-point tools go one step further and project from a third point you enter, the retracement end; this tool has no third-point input, so it anchors at the swing start instead. The current price field also deserves honesty: it never enters the size of any level. It only decides direction, upward measured from the low or downward measured from the high, and in Extensions mode the ladder chart draws only the High and Low labels, not the extension lines. Finally, downward extensions on a small range can print negative prices (a $100 to $200 swing with a current price below the low gives a 261.8% extension of -$61.80). Treat that as the formula running off the edge of the useful range, not as a price target.

What competing calculators miss

Five tools dominate this keyword, and each leaves a specific gap:

• MiniWebTool: clean start/end inputs and a price ladder, but its extension set stops at three levels (127.2%, 161.8%, 261.8%) and there are no custom levels, so a trader who watches 65% or 138.2% cannot get their number.
• JournalPlus: good level-by-level explanations, but only the five standard retracement ratios, no extensions at all, and no precision control for forex-priced swings.
• CalculatorsHub: the fastest of the group, five levels and a formula, but uptrend only in practice; its worked formula subtracts from the high with no downtrend mirror and no extension mode.
• BraveCalculator: solid educational copy around five levels, again with no custom ratios, no downtrend handling worth the name and nothing beyond the swing.
• UpFront Trading and the three-point school (MiniWebTool’s separate extension tool, Market-Bulls): their extensions need a third point, the retracement end, and project from it. More faithful to textbook method, but slower, and their levels shift with where that retracement ended, while this page anchors every extension at the swing start, as the section above spells out.
• The gap this page fills: both retracement directions with mirrored anchors, seven extension levels, custom levels up to 500%, decimal control to 8 places, a ladder chart, and a copyable level list, with the extension convention stated in plain words instead of buried.

Using the levels without fooling yourself

A Fibonacci level works, when it works, because thousands of traders placed orders at the same obvious prices. That makes levels useful as zones to watch and useless as guarantees, a distinction the SEC’s investor glossary entry on technical analysis makes in its own cautious wording.

Three habits separate traders who get value from these levels from traders who get noise. First, demand confluence: a 61.8% level that also sits on a prior swing high, a round number or a major moving average is a different proposition from a level floating in empty chart space. Second, match the timeframe to the trade; levels drawn on a daily swing survive contact with intraday noise far better than levels drawn on a five-minute swing. Third, write the plan before price arrives: entry zone, invalidation below the next level down, and a target at an extension, then judge the plan afterwards with something like the portfolio performance calculator rather than by how the chart felt. What this calculator will not do is pick your swing for you. Two traders measuring different swings on the same chart get different levels, and both sets of arithmetic are correct; the disagreement is about which move matters, and no calculator settles that. Trend strength is the other half of that confluence check: the average directional movement index calculator measures how one-sided price movement has been on Wilder’s ADX scale, so a level on a fading trend reads differently from one on a strong trend.

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