In Tableau, how do you modify the number of decimals of a percentage label? On bar charts, histograms, maps, etc.
Right Click on the measure dropped under Marks Card and Click on "Format". You will be provided with the options to change the format of the numbers in "Pane". Select "Numbers" and Click on the "Percentage" and increase/decrease the Percentage Decimals.
If you want that format choice to be the default for occurrences of that field on all worksheets, set the default property number format by right clicking on the field in the data pane (left margin) instead of on a shelf