Lazarus: Get Default Font Size of Application and Controls

If Font.Size is 0, that means, that the default font size should be used.

You can get the real size in the following way:

function GetDefaultFontSize: integer;
var
  fd: TFontData;
begin
  fd := GetFontData(prog.Font.Handle); 
  result := round((fd.Height * 72 / Font.PixelsPerInch) * (-1));  
end;

As you can see, I have written a small function for this, that should demonstrate how to proceed.

First of all, we are catching the FontData of the program ("prog" is our main form) and after that, we have to convert the value provided from this into the font size we can work with.
Last update on 2026-10-10 | Created on 2015-11-01