CSS units·104px
104px =
6.5rem
78pt

104 px in rem — 6.5 rem, 78 pt

104 px is 6.5 rem and 78 pt — 1.08333 inches, 27.517 mm, and 650% of the root font size.

rem (root 16 px)
6.5rem
pt (points)
78pt · exact
pc (picas)
6.5pc
percent of root
650%
inches
1.08333in
millimetres
27.517mm
centimetres
2.7517cm

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)
101px6.3125rem75.75pt
102px6.375rem76.5pt
103px6.4375rem77.25pt
104px6.5rem78pt
105px6.5625rem78.75pt
106px6.625rem79.5pt
107px6.6875rem80.25pt

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 104 px?

6.5 rem — that is 104 divided by 16.

Q. How many points is 104 px?

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

Q. What length is that?

1.08333 inches, or 27.517 mm — though a ruler on the screen will not agree.

Q. And as a percentage?

650% of the root font size.