Typical font-size values at 96 dpi

CSS

Ems

Points

Pixels

Percent

Heading

HTML

Physical Size

xx-small

0.50em

0.57em

6pt

7pt

8px

9px

50%

57%

10pixels

12pixels

x-small

0.63em

0.69em

0.75em

7.5pt

8pt

9pt

10px

11px

12px

63%

69%

75%

h6

1

2

12pixels

13pixels

14pixels

small

0.82em

0.88em

0.94em

9.75pt

10.5pt

11.25pt

13px

14px

15px

82%

88%

94%

h5

16pixels

17pixels

18pixels

medium

1em

1.08em

12pt

13pt

16px

17px

100%

108%

h4

3

18pixels

20pixels

large

1.13em

1.17em

1.25em

1.38em

13.5pt

14pt

15pt

16.5pt

18px

19px

20px

22px

113%

117%

125%

138%

h3

4

22pixels

23pixels

25pixels

26pixels

x-large

1.50em

1.75em

18pt

21pt

24px

28px

150%

175%

h2

5

29pixels

34pixels

xx-large

2em

24pt

32px

200%

h1

6

38pixels