Fibonacci Calculator

Fibonacci retracements come from a number sequence discovered 800 years ago. Each number is the sum of the two before it: 1, 1, 2, 3, 5, 8, 13, 21... and so on forever. Divide any number by the one after it and you get roughly 0.618. Divide by the one two places ahead and you get 0.382. Why do traders care about medieval math? Because these ratios appear everywhere in markets. After a strong move up or down, price tends to retrace to these levels before continuing. 38.2%, 50%, 61.8%—these aren't magic numbers, but they become self-fulfilling when enough traders watch them. Here's the practical bit: you draw Fibonacci from a swing low to a swing high (for uptrends) or high to low (for downtrends). The calculator plots horizontal lines at key retracement levels. When price pulls back to one of these lines, traders look for entry opportunities in the direction of the original trend. The 61.8% level—called the "golden ratio"—gets the most attention. It's often the last stand before a pullback becomes a full reversal.