CSS units·29px
29px =
1.8125rem
21.75pt

29 px in rem — 1.8125 rem, 21.75 pt

29 px is 1.8125 rem and 21.75 pt — 0.30208 inches, 7.673 mm, and 181.25% of the root font size.

rem (root 16 px)
1.8125rem
pt (points)
21.75pt
pc (picas)
1.8125pc
percent of root
181.25%
inches
0.30208in
millimetres
7.673mm
centimetres
0.7673cm

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)
26px1.625rem19.5pt
27px1.6875rem20.25pt
28px1.75rem21pt
29px1.8125rem21.75pt
30px1.875rem22.5pt
31px1.9375rem23.25pt
32px2rem24pt

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 29 px?

1.8125 rem — that is 29 divided by 16.

Q. How many points is 29 px?

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

Q. What length is that?

0.30208 inches, or 7.673 mm — though a ruler on the screen will not agree.

Q. And as a percentage?

181.25% of the root font size.