Calculate textsize depending on label height

You can use StringUtils.MeasureMultilineTextHeight to measure the text height. You can run it in a loop and check it with different text sizes to find the best size.

Direct calculation

You can calculate it the following way:

Label1.textsize = Label1.height * 500/1000dip

or use any other number than 500.

Text sizes are always scaled to screen density, whereas values for view dimensions are in pixels.

Alternatively, coming from the textsize you can do this.

Label1.height = Label1.textsize * 2000dip/1000

Why the 1000? If you use one dip, you get strange rounding effect.

ACtually, reading your question exactly, you say you set label sizes with dips, so the second way is the correct one.