CSS units·123px
123px =
7.6875rem
92.25pt

123 px in rem — 7.6875 rem, 92.25 pt

123 px is 7.6875 rem and 92.25 pt — 1.28125 inches, 32.544 mm, and 768.75% of the root font size.

rem (root 16 px)
7.6875rem
pt (points)
92.25pt
pc (picas)
7.6875pc
percent of root
768.75%
inches
1.28125in
millimetres
32.544mm
centimetres
3.2544cm

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)
120px7.5rem90pt
121px7.5625rem90.75pt
122px7.625rem91.5pt
123px7.6875rem92.25pt
124px7.75rem93pt
125px7.8125rem93.75pt
126px7.875rem94.5pt

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 123 px?

7.6875 rem — that is 123 divided by 16.

Q. How many points is 123 px?

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

Q. What length is that?

1.28125 inches, or 32.544 mm — though a ruler on the screen will not agree.

Q. And as a percentage?

768.75% of the root font size.