Each indicator uses different number of bars to show a value.

For Example 50 SMA needs 50 bars. Fractal needs 5-7 bars, MACD 26,12,9 needs 26 bars. Also several bars are needed for the logical condition (normally 2-3 bars).

PivotPoints on Daily basis need bars for 2 days. If we use 5 min chart we need 576 bars (2*24*60/5).

However, some indicators uses their previous values to calculate the current value. Such indicator is Exponential MA. Theoretically EMA uses all bars from data series. You have to decide how much bars to load depending on the EMA parameters.

Another case are WTF indicators. They need bars to cover the bars from selected time frame. They also depends on the periods and the difference between main time frame and WTF indicator time frame.

FSB calculates the minimum required bars for the standard indicators. You can calculate that number as a difference between Number of Data Bars and Tested Bars.

Here Required Bars are 41 = 5715 - 5674