inches to cm converter

How to convert inches to centimeters

Multiply inches by 2.54 and you have centimetres. The factor is exact, not a rounded 2.5, because the inch is defined as 25.4 millimetres. One inch is 2.54 cm, six inches is 15.24 cm, and a foot of inches (12) is 30.48 cm, which is the same 0.3048 m the feet-to-meters page uses. If those two pages ever disagreed, one of them would be wrong. They call the same factor table.

This is the direction for a US or UK measurement that has to land in a metric drawing, a shipping form in centimetres, or a medical height that was taken in inches. A 27-inch diagonal is 68.58 cm. That is the diagonal, so do not treat it as the width of the set.

Exact formula

Formulacentimeters = inches × 2.54

centimeters = inches × 2.54 One in is 2.54 cm. Ten in is 25.4 cm. The worked example below uses that same conversion.

Conversion table

The inches column runs from 1 in (2.54 cm) through 60 in (152.4 cm).

Worked example: Inches to Centimeters

One inch is 2.54 cm by definition, so any chart that prints 2.5 has already rounded the inch away. Twelve inches, one foot, is 30.48 cm, the same 30.48 cm the foot pages use. A 27-inch display diagonal is 68.58 cm. That figure is the diagonal of the panel, not the width of the stand and not the centimetres of desk it needs. Fractional inches such as 3/8 have to become 0.375 before you multiply by 2.54.

Pitfalls for inches to centimeters

• Fractional inches such as 3/8 are 0.375, not 0.38, if you need the exact product 0.375 × 2.54.
• Display sizes and tyre sizes mix inches with other conventions. Read which dimension is the inch.
• Survey measure is not this inch. For ordinary lengths the international inch is the one on the ruler.
• Multiplying by 2.5 and then 'fixing' the result by eye will not match a part that was cut at 2.54.