Enter values below to convert centimeter [cm] to inch [in], or the other way around.
📏 Centimeter (cm)
What It Is: A centimeter is a unit of length in the International System of Units (SI)—the modern metric system used around the world. It represents one-hundredth of a meter, making it ideal for measuring smaller distances with precision.
Where It Comes From: The word "centimeter" combines centi- (meaning one hundredth) with meter, the SI base unit for length. The metric system is built on a decimal structure, using prefixes like milli-, centi-, kilo-, and mega- to scale measurements up or down. Understanding these prefixes makes it easier to navigate scientific and everyday measurements.
How It’s Used Today: Centimeters are widely used in countries that follow the metric system. You’ll often see them used to measure height, dimensions of objects, or distances that are too small for meters but too large for millimeters. While the United States still relies heavily on inches, centimeters are the go-to unit in most of Europe, Asia, and beyond.
📐 Inch (in)
What It Is: An inch is a unit of length used in the imperial and US customary systems. Since 1959, it’s been officially defined as exactly 25.4 millimeters. There are 12 inches in a foot and 36 inches in a yard.
Where It Comes From: The term "inch" traces back to the Latin word uncia, meaning one-twelfth of a Roman foot. Historically, the inch has had several definitions—one quirky version equated it to the length of three barleycorns laid end-to-end. Another old method involved averaging the width of three human thumbs (small, medium, and large).
How It’s Used Today: Inches remain standard in the United States, Canada, and the United Kingdom, especially in construction, manufacturing, and consumer products. They’re also commonly used in Japan and other countries when referring to screen sizes, such as TVs, monitors, and smartphones.
📏 Centimeter to Inch Conversion Guide
Need to convert centimeters to inches? Whether you're working on a project, studying for an exam, or just curious, this quick reference table and guide will help you make accurate conversions with ease.
🔢 Conversion Table
| Centimeters (cm) | Inches (in) |
|---|---|
| 0.01 cm | 0.0039 in |
| 0.1 cm | 0.0394 in |
| 1 cm | 0.3937 in |
| 2 cm | 0.7874 in |
| 3 cm | 1.1811 in |
| 5 cm | 1.9685 in |
| 10 cm | 3.9370 in |
| 20 cm | 7.8740 in |
| 50 cm | 19.6850 in |
| 100 cm | 39.3701 in |
| 1000 cm | 393.7008 in |
Rounded to 4 decimal places for simplicity.
🧮 How to Convert
- From centimeters to inches: Multiply the length in centimeters by 0.3937
1 cm = 0.3937 in - From inches to centimeters: Multiply the length in inches by 2.54
1 in = 2.54 cm
✏️ Example Conversion
Convert 15 cm to inches: 15 cm × 0.3937 = 5.9055 in
So, 15 centimeters is approximately 5.91 inches.
💻 Behind the Scenes: The Logic That Powers This Converter
// Centimeter to Inch Converter
function convertCMtoInch(cm) {
return cm * 0.3937007874;
}
// Example usage:
let cm = 15;
let inches = convertCMtoInch(cm); // 5.9055