CSS units·121px
121px =
7.5625rem
90.75pt

121 px in rem — 7.5625 rem, 90.75 pt

121 px is 7.5625 rem and 90.75 pt — 1.26042 inches, 32.015 mm, and 756.25% of the root font size.

rem (root 16 px)
7.5625rem
pt (points)
90.75pt
pc (picas)
7.5625pc
percent of root
756.25%
inches
1.26042in
millimetres
32.015mm
centimetres
3.2015cm

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)
118px7.375rem88.5pt
119px7.4375rem89.25pt
120px7.5rem90pt
121px7.5625rem90.75pt
122px7.625rem91.5pt
123px7.6875rem92.25pt
124px7.75rem93pt

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 121 px?

7.5625 rem — that is 121 divided by 16.

Q. How many points is 121 px?

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

Q. What length is that?

1.26042 inches, or 32.015 mm — though a ruler on the screen will not agree.

Q. And as a percentage?

756.25% of the root font size.