CSS units·103px
103px =
6.4375rem
77.25pt

103 px in rem — 6.4375 rem, 77.25 pt

103 px is 6.4375 rem and 77.25 pt — 1.07292 inches, 27.252 mm, and 643.75% of the root font size.

rem (root 16 px)
6.4375rem
pt (points)
77.25pt
pc (picas)
6.4375pc
percent of root
643.75%
inches
1.07292in
millimetres
27.252mm
centimetres
2.7252cm

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)
100px6.25rem75pt
101px6.3125rem75.75pt
102px6.375rem76.5pt
103px6.4375rem77.25pt
104px6.5rem78pt
105px6.5625rem78.75pt
106px6.625rem79.5pt

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 103 px?

6.4375 rem — that is 103 divided by 16.

Q. How many points is 103 px?

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

Q. What length is that?

1.07292 inches, or 27.252 mm — though a ruler on the screen will not agree.

Q. And as a percentage?

643.75% of the root font size.