Convert inches to cm

Since 1959, the inch has been defined internationally as exactly 2.54 cm. To convert inches to centimetres, multiply by 2.54. To go the other way, divide by 2.54. The converter also understands fractions such as 3/8 or 1 1/2.

Updated 7 October 2026 by the editorial team

Contents of this page

Inches to cm

InchesFractions such as 3/8 or 1 1/2 work too

Centimetres

Table: inches to centimetres

Inches	cm	mm
1/8 in	0.318 cm	3.18 mm
1/4 in	0.635 cm	6.35 mm
3/8 in	0.953 cm	9.53 mm
1/2 in	1.27 cm	12.7 mm
3/4 in	1.905 cm	19.05 mm
1 in	2.54 cm	25.4 mm
2 in	5.08 cm	50.8 mm
3 in	7.62 cm	76.2 mm
4 in	10.16 cm	101.6 mm
5 in	12.7 cm	127 mm
6 in	15.24 cm	152.4 mm
8 in	20.32 cm	203.2 mm
8.5 in	21.59 cm	215.9 mm
10 in	25.4 cm	254 mm
11 in	27.94 cm	279.4 mm
12 in	30.48 cm	304.8 mm
14 in	35.56 cm	355.6 mm
17 in	43.18 cm	431.8 mm
24 in	60.96 cm	609.6 mm
36 in	91.44 cm	914.4 mm

Where you meet inches

Paper: US sizes such as Letter (8.5 × 11 in) and Legal (8.5 × 14 in). US paper sizes
Screens: Diagonals are given in inches. A 27-inch monitor has a 68.6 cm diagonal.
Photos: Photo prints in the UK and US are named in inches: 6 × 4, 7 × 5, 10 × 8. Photo print sizes
Print: dpi means dots per inch, which is why every pixel conversion contains the factor 2.54.
Books: American trim sizes such as 6 × 9 inches. US book trim sizes

Where the inch comes from

The inch started out as a body measure, roughly the width of a thumb, and its length varied from country to country. Since 1959, the international inch has been fixed at exactly 25.4 mm by agreement between the US, the UK and other Commonwealth countries. In the UK, inches are still common in everyday life alongside metric units, from screen sizes to photo prints.

Frequently asked questions

How many cm is 1 inch?

Exactly 2.54 cm.

How many inches is 1 cm?

About 0.3937 inches.

How many cm is 27 inches?

68.58 cm.

How many cm is 8.5 × 11 inches?

21.59 × 27.94 cm, the US Letter size.