A number of periods (n) should be chosen for calculation of the RSI (unit of the covered period are usually calculated in the form of daily, weekly, or monthly basis). Then, the RSI can be calculated using the following formula:

The RSI has a value between 0 and 100. A lower level and an upper level should be shown to indicate oversold and overbought levels. Typically, the upper and lower levels are recognized at 70 and 30, respectively. When the RSI moves below the lower level and reverses direction, a bullish buy signal appears. When the RSI moves above the upper level and peaks, a bearish sell signal occurs. The most commonly used time spans (n) are 10 days and 14 days. However, you can still enter your preferred time span in the top right hand side of our Java Charting System.