CM to Inches Converter

How to convert centimeters to inches?

Converting centimeters to inches is one of the most-searched unit conversions online, used daily for clothing sizes, screen dimensions, furniture, height, paper formats, and international shopping. One inch equals exactly 2.54 centimeters, so the conversion divides centimeters by 2.54. Useful landmarks: 2.54 cm is exactly 1 inch, 10 cm is about 3.94 inches, 30 cm (a typical ruler) is roughly 11.81 inches, and 100 cm equals about 39.37 inches. Our tool shows decimal inches, fractional inches (eighths and sixteenths), and a feet-plus-inches breakdown for human-height conversions.

d_(in) = d_(cm) / 2.54

Example

Convert 10 cm to inches:

d_(in) = 10cm / 2.54 = 3.93701in

How many inches in a centimeter?

There are approximately 0.393701 inches in one centimeter, the reciprocal of 2.54. So a centimeter is a little less than half an inch. For mental shortcuts, 1 cm is roughly 2/5 inch, 2.5 cm is essentially 1 inch, 5 cm is about 2 inches, and 30 cm (a school ruler) is just under 12 inches (one foot). For precise work, always multiply by 0.393701 rather than rounding, especially when adding multiple measurements where rounding errors accumulate over long distances.

How many centimeters in an inch?

There are exactly 2.54 centimeters in one inch. This is a defined relationship since the 1959 International Yard and Pound Agreement, not a measured approximation. So 1 inch is 2.54 cm, 2 inches is 5.08 cm, 12 inches (one foot) is 30.48 cm, and 36 inches (one yard) is 91.44 cm. The clean factor of 2.54 makes manual conversion straightforward: shift the decimal and adjust slightly. Tape measures sold in metric countries often print both scales for convenience.

What is the conversion formula?

The formula is inches = centimeters divided by 2.54. Equivalently, multiply by 0.393701. For example, 10 cm divided by 2.54 equals 3.937 inches, and 100 cm equals 39.37 inches. Some calculators show the result as feet plus inches (5 feet 6 inches), or as a fraction like 3 and 15/16 inches, since US tape measures use sixteenths rather than decimals. Our tool provides all three formats so you can pick the most useful for your project.

How do I convert my height from cm to feet and inches?

First divide cm by 2.54 to get total inches, then divide by 12 to get feet, with the remainder as inches. Example: 170 cm divided by 2.54 equals 66.93 inches. Divide 66.93 by 12 to get 5 feet with 6.93 inches remaining, which rounds to 5 feet 7 inches. Quick reference: 150 cm is 4 feet 11 inches, 160 cm is 5 feet 3 inches, 170 cm is 5 feet 7 inches, 180 cm is 5 feet 11 inches, and 190 cm is 6 feet 3 inches.

Why is the cm to inch ratio exactly 2.54?

It became exact only in 1959, when the US, UK, and Commonwealth nations agreed to redefine the inch as exactly 25.4 millimeters (so 2.54 centimeters). Before that, the inch was defined separately in each country based on national prototype bars, with values differing by a few millionths. The redefinition standardized international trade in machined parts, aerospace components, and scientific instruments. The choice of 25.4 mm was a slight rounding of the old US inch and the old UK inch to a common value.

What is a centimeter, exactly?

A centimeter is exactly 1/100 of a meter, or 10 millimeters. The meter itself is defined since 1983 as the distance light travels in vacuum in 1/299,792,458 second, making the centimeter equally precise and universally reproducible. Centimeters are the everyday metric unit for human-scale objects: book sizes, monitor screens, body measurements, ruler lengths, and most furniture dimensions. Smaller measurements use millimeters; larger ones use meters or kilometers. The centimeter sits comfortably between for typical household work.

What is an inch, exactly?

The international inch is defined as exactly 25.4 millimeters, fixed by the 1959 International Yard and Pound Agreement. There are 12 inches in a foot, 36 inches in a yard, and 63,360 inches in a mile. The word inch comes from the Latin 'uncia' meaning one-twelfth. Inches are the dominant length unit in the US for personal measurements, paper sizes, screen diagonals, lumber, and clothing inseams. The UK uses inches for the same purposes plus some traffic signs and household measurements.

Popular cm to inches conversion table