How Fibonacci levels are calculated
In an uptrend: level = high − (high − low) × ratio. With a swing from 2,380 to 2,450 on gold, the 61.8% retracement is 2,450 − 70 × 0.618 = 2,406.7.
Extensions project the move beyond the swing: in an uptrend, low + range × 1.618 gives the 161.8% target.
Using Fibonacci with a stop loss
Traders often enter near 50-61.8% and place the stop beyond 78.6%. Measure that distance with the risk/reward calculator before taking the trade.