Convert Centimeter to Inch (cm → in)

Converting centimeters to inches is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.

1. 1
   Take your value in centimeters

   Start with the number of centimeters (cm) you want to convert.
2. 2
   Multiply by 0.393701

   The conversion factor from cm to in is 0.393701. Multiply your value by this number.
3. 3
   Read the result in inches

   The result is your value in inches (in).

Multiply the value in centimeters by 0.393701. For the reverse direction, multiply by 2.54.

• ✓1 cm ≈ 0.394 inches — divide cm by 2.54 for a precise inch conversion.
• ✓Your little finger is about 1 cm wide at the nail — useful when no ruler is nearby.
• ✓100 cm = 1 metre exactly. Always convert to metres for architectural plans.

• ✗Confusing linear cm with square cm. 21 cm of ribbon is not the same as 21 cm² of fabric.
• ✗Using 2.5 instead of 2.54 for inch conversion — the 1.6% error grows on long measurements.
• ✗Reading a clothing size label as cm when it is actually an EU size code (e.g. size 42 ≠ 42 cm).

What is the Centimeter?

The centimeter equals one hundredth of a meter (0.01 m) and is the everyday metric unit for body measurements, clothing, furniture, and household items. It bridges the gap between the meter (too large for personal items) and the millimeter (too small for clothing). The centimeter is widely used in countries with metric systems for height (a person is 160–185 cm tall), paper sizes (A4 is 21 × 29.7 cm), and medical measurements. Although not strictly an SI base unit, it is one of the most common units in daily metric usage. The centimeter relates to the inch (1 cm ≈ 0.394 in) and to the millimeter (1 cm = 10 mm). It became standard with the metric system's adoption across continental Europe in the 19th century.

• Height and body measurements in medical records
• Ready-to-wear clothing sizes in Europe and Asia
• Furniture and interior design dimensions

What is the Inch?

The inch equals exactly 25.4 millimeters under the 1959 international yard and pound agreement. The word derives from the Old English 'ynce,' from Latin 'uncia' meaning one twelfth (the inch is one twelfth of a foot). Originally based on the width of a thumb, the inch has been standardized for centuries. It is the global standard for screen sizes (a 15-inch laptop or 65-inch TV), pipe and tubing diameters (1-inch plumbing, 2-inch exhaust), and shoe sizes in Anglo-Saxon countries. Construction lumber, photographic prints, paper sizes (US Letter is 8.5 × 11 in), and rainfall in the US all use inches. The inch relates to the millimeter (25.4 mm = 1 in exactly), the foot (12 in = 1 ft), and the yard (36 in = 1 yd). Subdivisions in fractions (½, ¼, ⅛) remain common in carpentry.

• Screen and monitor diagonals worldwide (phone, tablet, TV)
• US and UK shoe sizes
• Industrial pipe and fitting diameters