CSS units·46px
46px =
2.875rem
34.5pt

46 px in rem — 2.875 rem, 34.5 pt

46 px is 2.875 rem and 34.5 pt — 0.47917 inches, 12.171 mm, and 287.5% of the root font size.

rem (root 16 px)
2.875rem
pt (points)
34.5pt
pc (picas)
2.875pc
percent of root
287.5%
inches
0.47917in
millimetres
12.171mm
centimetres
1.2171cm

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)
43px2.6875rem32.25pt
44px2.75rem33pt
45px2.8125rem33.75pt
46px2.875rem34.5pt
47px2.9375rem35.25pt
48px3rem36pt
49px3.0625rem36.75pt

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 46 px?

2.875 rem — that is 46 divided by 16.

Q. How many points is 46 px?

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

Q. What length is that?

0.47917 inches, or 12.171 mm — though a ruler on the screen will not agree.

Q. And as a percentage?

287.5% of the root font size.