Convert Centimeters (cm) to Inches (in)

Centimeters and inches are two of the most commonly used units of length. One centimeter equals approximately 0.393701 inches, or equivalently, one inch equals exactly 2.54 centimeters. This converter makes it easy to switch between metric and imperial length measurements for everyday tasks, crafts, and engineering.

0.393701

= 4.72 in

25/64 in

Conversion Formula

inches = cm × 0.393701

Reverse: cm = inches × 2.54

Quick mental math: Divide by 2.5 for a quick estimate

Conversion Examples

1 cm × 0.393701 =
0.394 in
1 Centimeters = 0.394 Inches
5 cm × 0.393701 =
1.969 in
5 Centimeters = 1.969 Inches
10 cm × 0.393701 =
3.937 in
10 Centimeters = 3.937 Inches
25 cm × 0.393701 =
9.843 in
25 Centimeters = 9.843 Inches
50 cm × 0.393701 =
19.685 in
50 Centimeters = 19.685 Inches
100 cm × 0.393701 =
39.37 in
100 Centimeters = 39.37 Inches

Centimeter to Inch Table

cm =in
Centimeter (cm)Inch (in)
10.3937
20.7874
31.1811
41.5748
51.9685
62.3622
72.7559
83.1496
93.5433
103.937
114.3307
124.7244
135.1181
145.5118
155.9055
166.2992
176.6929
187.0866
197.4803
207.874

Unit Definitions

What is a Centimeter (cm)?

Metric (SI)Worldwide (except US)

A centimeter is a unit of length in the metric system equal to one hundredth of a meter (0.01 m). It is part of the International System of Units (SI).

History

The centimeter was introduced as part of the metric system in France in 1795. The metric system was created during the French Revolution to establish a universal, rational system of measurement. The centimeter became widely adopted globally throughout the 19th and 20th centuries.

Current Use

Centimeters are used worldwide for everyday measurements including body height, object dimensions, and clothing sizes. They are the default small-length unit in most countries outside the United States.

Learn more about Centimeter

What is a Inch (in)?

ImperialUnited States, United Kingdom, Canada

An inch is a unit of length in the imperial and US customary systems, defined as exactly 2.54 centimeters or 1/12 of a foot.

History

The inch has roots in ancient measurement systems, originally based on the width of a human thumb. The word comes from the Latin 'uncia,' meaning one-twelfth. In 1959, the international yard and pound agreement standardized the inch at exactly 25.4 millimeters.

Current Use

Inches are primarily used in the United States, United Kingdom, and Canada for everyday measurements. They are standard for measuring screen sizes, paper dimensions, and construction materials.

Learn more about Inch

Frequently Asked Questions

How many inches are in 1 cm?
One centimeter is equal to approximately 0.393701 inches. This conversion factor is derived from the international standard where one inch is defined as exactly 2.54 centimeters. To convert any centimeter value to inches, simply multiply by 0.393701. For example, 5 cm equals about 1.9685 inches.
What is the formula to convert cm to inches?
The formula to convert centimeters to inches is: inches = centimeters × 0.393701. Alternatively, you can divide the centimeter value by 2.54 to get the same result. Both methods are mathematically equivalent and will give you an accurate conversion. The factor 2.54 is exact by international agreement since 1959.
How do I convert 30 cm to inches?
To convert 30 cm to inches, multiply 30 by 0.393701, which gives you 11.81103 inches. Rounded to two decimal places, 30 cm equals approximately 11.81 inches. This is just under one foot (12 inches). This conversion is commonly needed when measuring screen sizes, document dimensions, or clothing measurements.
Why is the cm to inches conversion factor 0.393701?
The conversion factor 0.393701 is the reciprocal of 2.54, which is the exact number of centimeters in one inch. The international yard and pound agreement of 1959 defined one inch as exactly 25.4 millimeters (2.54 centimeters). Dividing 1 by 2.54 gives approximately 0.393701, which represents how many inches fit in one centimeter.
Is the cm to inches conversion exact or approximate?
The conversion from inches to centimeters is exact: 1 inch = 2.54 cm by international definition. However, when converting cm to inches, the result of 0.393701 is a rounded approximation of the repeating decimal 1/2.54. For most practical purposes, using 0.393701 provides accuracy to six significant figures, which is more than sufficient for everyday measurements.

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