You have to consider annular ring for the hole to pad dimensions.
Solder mask has to be slighly oversized to allow for slight misalignment, historically it has been 0.008" ish, it can be smaller but that makes it harder for the manufacturer & that costs more.
On fine pitch IC's you may have a block of missing solder mask rather than individual pads.
for paste, SMT pads - leave 1:1 and the screen manufacturer will reduce them as required.
pth pads - as they are generally round - identify that they ned removing from the screen.
or if you can reassign a zero size in your CAD package that will ensure they are not used when making the Gerber.