CM to Inch Converter

Convert centimeters to inches (and back) instantly using the exact international standard formula. Free, accurate, and works on any device.

Quick Converter

3.937008 in

Common CM to Inch Conversions

Centimeters (cm) Inches (in) Feet & Inches
1 cm 0.3937 in —
5 cm 1.9685 in —
10 cm 3.9370 in —
15 cm 5.9055 in —
30 cm 11.8110 in —
60 cm 23.6220 in 1′ 11.62″
100 cm 39.3701 in 3′ 3.37″
150 cm 59.0551 in 4′ 11.06″
170 cm 66.9291 in 5′ 6.93″
180 cm 70.8661 in 5′ 10.87″
200 cm 78.7402 in 6′ 6.74″

Understanding CM to Inch Conversion

The centimeter (cm) is a unit of length in the metric system, widely used in most countries worldwide. The inch (in) belongs to the imperial system, primarily used in the United States, United Kingdom, and Canada. Converting between the two is a routine need in fashion, engineering, design, and everyday life.

The exact relationship between centimeters and inches was standardized in 1959 under the international yard and pound agreement, making all conversions perfectly precise — not approximations.

Conversion Formula

The internationally accepted conversion factor is: 1 inch = 2.54 cm exactly.

cm → inches:   inches = centimeters ÷ 2.54
inches → cm:   centimeters = inches × 2.54
Quick tip: To convert 10 cm to inches, simply calculate 10 ÷ 2.54 = 3.937 inches.

Example Calculations

  • 30 cm to inches: 30 ÷ 2.54 = 11.81 inches
  • 12 inches to cm: 12 × 2.54 = 30.48 cm
  • 170 cm to inches: 170 ÷ 2.54 = 66.93 inches (5 ft 6.93 in)
  • 6 inches to cm: 6 × 2.54 = 15.24 cm
  • 100 cm to inches: 100 ÷ 2.54 = 39.37 inches

Why Accurate Conversion Matters

Precise centimeter-to-inch conversion is critical in fields such as architecture, interior design, manufacturing, and medicine. Using an incorrect ratio — even by a fraction — can cause significant errors in blueprints, garment sizing, or equipment specifications.

This converter uses the exact 2.54 ratio defined by the 1959 International Yard and Pound Agreement, not a rounded approximation, ensuring professional-grade accuracy.

Frequently Asked Questions

How many inches are in one centimeter?

There are exactly 0.3937007874 inches in one centimeter, based on the 1959 international standard.

How many centimeters are in one inch?

There are exactly 2.54 centimeters in one inch. This is the internationally defined value.

How do I convert centimeters to inches manually?

Divide the number of centimeters by 2.54. For example, 50 cm ÷ 2.54 = 19.685 inches.

What is 170 cm in feet and inches?

170 cm equals approximately 5 feet 6.93 inches (or 66.93 inches total).

Is this conversion accurate?

Yes. This converter uses the exact internationally recognized conversion ratio defined in 1959 — 1 inch = 2.54 cm — with no rounding in intermediate steps.

Can I use this converter on mobile?

Yes. This tool is fully responsive and optimized for smartphones and tablets, with automatic light and dark mode support.