William Morder via tde-users wrote:
I clicked size, then you see that the display window
to the right has
values for the aspect ratio, height x width; mine were set for 364,357,
which I just doubled, to 728,714, and voila! the interface itself is now
doubled, though not the font size for buttons, nor the fonts in the
interface itself.
To change the display of the kcalc
1. Open kcalc
2. click Settings
3. Choose Font Size as it fits
4. press OK
For the buttons, you may also try setting the DPI from the control center
(TCC)
I have it set to enforced 120
it is under Fonts