How to Convert Inches to Centimeters (and Back)
Inches and centimeters are the two most common units for measuring short distances in everyday life — height, screen sizes, rulers, clothing measurements. The United States uses inches; almost everywhere else uses centimeters. This guide gives you the exact conversion, a height reference table, and practical tips for the most common use cases.
What Is an Inch?
An inch (in or ″) is an imperial unit of length equal to exactly 2.54 centimeters. It is the standard unit for short measurements in the United States — height, screen sizes, pipe diameters, and most hardware.
The inch has been defined in terms of the metric system since 1959, when the international yard and pound agreement fixed 1 inch = 2.54 cm exactly. Before that, slight variations existed between the US and UK definitions.
What Is a Centimeter?
A centimeter (cm) is one-hundredth of a meter. It is the standard unit for short lengths in the metric system — height, clothing sizes, room dimensions, and most everyday measurements outside the United States.
One centimeter is roughly the width of a fingernail. A standard school ruler is 30 cm long, which equals about 11.8 inches.
The Conversion Formula
1 inch = 2.54 centimeters (exact, by international definition).
To convert inches to centimeters: multiply by 2.54. For example, 6 inches × 2.54 = 15.24 cm.
To convert centimeters to inches: divide by 2.54 (or multiply by 0.393701). For example, 30 cm ÷ 2.54 = 11.81 inches.
Mental shortcut: multiply inches by 2.5 for a quick estimate. The result is about 1.6% low — close enough for casual use.
Height Conversion Reference
Common heights in feet/inches and centimeters:
- 5'0″ (60 in) = 152.4 cm
- 5'4″ (64 in) = 162.6 cm
- 5'6″ (66 in) = 167.6 cm
- 5'8″ (68 in) = 172.7 cm
- 5'10″ (70 in) = 177.8 cm
- 6'0″ (72 in) = 182.9 cm
- 6'2″ (74 in) = 188.0 cm
- 6'4″ (76 in) = 193.0 cm
Screen Size and Tech Measurements
Screen sizes are always measured in inches diagonally — even in countries that otherwise use centimeters. A 27-inch monitor measures 68.6 cm diagonally. A 65-inch TV is 165.1 cm.
Other tech measurements in inches: hard drive disk diameter (3.5″ or 2.5″), camera sensor sizes, paper sizes (US Letter is 8.5 × 11 inches = 21.6 × 27.9 cm).
Clothing: US measurements for waist, chest, and inseam are in inches. EU clothing uses centimeters. A 32-inch waist is 81.3 cm.
Converting Feet and Inches to Centimeters
To convert a height given in feet and inches (e.g., 5'9″) to centimeters:
1. Convert feet to inches: 5 × 12 = 60 inches.
2. Add the remaining inches: 60 + 9 = 69 inches total.
3. Multiply by 2.54: 69 × 2.54 = 175.3 cm.
Conclusion
1 inch = 2.54 cm exactly. To convert, multiply inches by 2.54 — or divide centimeters by 2.54 for the reverse. For screen sizes, always use the exact value. For quick mental math, multiplying by 2.5 gives a result within 1.6%. Use our free length converter for any value instantly.