CSS units·109px
109px =
6.8125rem
81.75pt

109 px in rem — 6.8125 rem, 81.75 pt

109 px is 6.8125 rem and 81.75 pt — 1.13542 inches, 28.84 mm, and 681.25% of the root font size.

rem (root 16 px)
6.8125rem
pt (points)
81.75pt
pc (picas)
6.8125pc
percent of root
681.25%
inches
1.13542in
millimetres
28.84mm
centimetres
2.884cm

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)
106px6.625rem79.5pt
107px6.6875rem80.25pt
108px6.75rem81pt
109px6.8125rem81.75pt
110px6.875rem82.5pt
111px6.9375rem83.25pt
112px7rem84pt

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 109 px?

6.8125 rem — that is 109 divided by 16.

Q. How many points is 109 px?

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

Q. What length is that?

1.13542 inches, or 28.84 mm — though a ruler on the screen will not agree.

Q. And as a percentage?

681.25% of the root font size.