Pt font in the layout and px font in the layout should not be 1 in 1?

Question

Layout

I ordered to make up a layout from a typesetter. If the font in the psd layout is 18pt, then how much should it be in px on the site?

I just made a layout designer 1 in 1, i.e. where 18pt, 18px

Answer 1

pixel units - 1px is equal to 0.75pt.
those. 18 points (pt) equals 24 pixels (px)
https://www.w3.org/TR/CSS21/syndata.html#x39

Answer 2

https://habr.com/ru/post/42151/