CSS units·58px
58px =
3.625rem
43.5pt

58 px in rem — 3.625 rem, 43.5 pt

58 px is 3.625 rem and 43.5 pt — 0.60417 inches, 15.346 mm, and 362.5% of the root font size.

rem (root 16 px)
3.625rem
pt (points)
43.5pt
pc (picas)
3.625pc
percent of root
362.5%
inches
0.60417in
millimetres
15.346mm
centimetres
1.5346cm

Why rem divides by 16

Because browsers default the root font size to 16 px, and rem is a multiple of it. When a reader enlarges text in their browser settings, only the parts written in rem grow — anything pinned in px stays put.

Nearby sizes

pxrem (root 16 px)pt (points)
55px3.4375rem41.25pt
56px3.5rem42pt
57px3.5625rem42.75pt
58px3.625rem43.5pt
59px3.6875rem44.25pt
60px3.75rem45pt
61px3.8125rem45.75pt

On screen, pt and inches are still pixels

CSS fixes one inch at 96 px and one point at 1/72 inch. So 16 px is exactly 12 pt — but hold a ruler to the screen and that "inch" will not measure an inch.

Sizes you meet most

Body text at 16, small text at 14, spacing at 8, 24 and 32 — the values that keep coming back.

How to read this

  • rem = px ÷ 16, because browsers default the root font size to 16 px.
  • pt = px × 0.75, since CSS fixes an inch at 96 px and a point at 1/72 inch.
  • One pc is 12 pt, and one inch is both 96 px and 72 pt.
  • Use rem for text and spacing; keep px for hairlines such as borders.

Frequently asked questions

Q. How many rem is 58 px?

3.625 rem — that is 58 divided by 16.

Q. How many points is 58 px?

43.5 pt. A point is 1/72 inch and an inch is 96 px, so you multiply by 0.75.

Q. What length is that?

0.60417 inches, or 15.346 mm — though a ruler on the screen will not agree.

Q. And as a percentage?

362.5% of the root font size.