The calculation will be done in ascending order - first price in the entered row will be used first in the calculations. Relative Strength measures a stock's price change over the last X months relative to the price change of a market index. Result in the table will be represented in the descending order - first price in the entered row will be at the bottom of the table of results. Relative strength is a measure of the price trend of a stock or other financial instrument compared to another stock, instrument or industry. It shows the relative outperformance or … To calculate Relative Strength Index (RSI), select RSI bar period and input prices separated by comma. Developed by J. Welles Wilder, the Relative Strength Index (RSI) is a momentum oscillator that measures the speed and change of price movements. According to Wilder, RSI is considered overbought when above 70 and oversold when below 30. RSI oscillates between zero and 100. Calculating an indicator allows you a better grasp of its uses. Signals can also be generated by looking for divergences, failure swings and centerline crossovers. You should know that. In this post, we'll teach you how to calculate the relative strength index step by step.