Hi there,

 

So I'm currently setting my laptop to match my desktop and on my laptop I scale the resolution to 125%. When I used the desktop scale tool on the calculator to convert 800dpi on my 24.5'' monitor to my 14'' laptop at 125% scaling is gae me 1120. Should this not be 1050? At 100% on my laptop it converts from 800 to 1400 so bearing that in mind 25% would be 350 so minus that off 1400 and I should be left with 1050 dpi for my laptop. Am I being a stupid here?

Cheers,

Pabs

4 minutes ago, ProfessorPabs said:

At 100% on my laptop it converts from 800 to 1400 so bearing that in mind 25% would be 350 so minus that off 1400 and I should be left with 1050 dpi for my laptop.

It's 1400/1.25=1120. With the display scale set to 125% the cursor is already 25% too fast, so you need to reduce it by 20% to get to 100% (so multiply by 0.8 or divide by 1.25).

Wait but if it’s 25% too fast then you need to reduce it by 25% no?

Just now, ProfessorPabs said:

Wait but if it’s 25% too fast then you need to reduce it by 25% no?

No, this is a common mistake.

Let's swap DPI for money in an example

If you purchase an item for $1000 and the tax is 25% you pay (1000*1.25) $1250.
If you want to find out what the price was before tax, you don't reduce $1250 by 25%, that would give you (1250*0.75) $937.5.
Instead you divide it by 1.25, so 1250/1.25=1000, or you can flip it and reduce it by 20% because 1/1.25=0.8.

It's the same with the DPI, you don't want to reduce it by 25%, you want to reduce it to what 100% is.