A centimeter (cm) is a metric unit of length equal to one‑hundredth of a meter. It is widely used in scientific, engineering, and everyday contexts worldwide.
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An inch (in) is an imperial unit of length defined as exactly 2.54 centimeters. It remains common in the United States, United Kingdom, and in many manufacturing specifications.
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Practical Applications
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Design drawings: dimensions are often given in centimeters for metric‑based projects and inches for legacy equipment.
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Manufacturing: bolt sizes, pipe diameters, and sheet‑metal thickness may be specified in either unit.
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Everyday life: measuring furniture, clothing, or personal height.
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The conversion factor is \\(1\\,\\text{cm}=0.3937007874015748\\,\\text{in}\\). Using this factor you can translate any metric length into the imperial system.
Centimeter to Inch Conversion Reference Table
Centimeter (cm)
Inch (in)
0.1
0.0394
0.5
0.1969
1.0
0.3937
2.0
0.7874
5.0
1.9685
10.0
3.937
20.0
7.874
50.0
19.685
100.0
39.3701
500.0
196.8504
1000.0
393.7008
Step‑by‑Step Conversion Example
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Convert 10 cm to inches.
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Write the known value: 10 cm.
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Multiply by the conversion factor \(0.3937007874015748\,\frac{\text{in}}{\text{cm}}\).
The international inch was re‑defined in 1959 as exactly 25.4 mm, which is 2.54 cm. This definition provides a precise, reproducible standard that aligns the imperial system with the metric system for engineering and scientific work.
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The factor is exact because it is derived from the definition 1 in = 2.54 cm. For most practical purposes you can round it to 0.3937 or 0.394, which yields errors well below 0.1 % for typical lengths.
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"On fait la science avec des faits, comme on fait une maison avec des pierres ; mais une accumulation de faits n'est pas plus une science qu'un tas de pierres n'est une maison." "Science is built up of facts, as a house is built of stones; but an accumulation of facts is no more a science than a heap of stones is a house." — Henri Poincaré (French Mathematician, Theoretical Physicist & Mining Engineer)