Cm to inches

Inches

Definition

An inch, represented by the symbols in or ", is a unit of length in the imperial and United States customary systems of measurement. One inch is defined as 1/12th of a foot or precisely 25.4 millimeters in the metric system.

History/Origin

The term "inch" derives from the Latin word "uncia," meaning "one-twelfth." Historically, an inch was equivalent to the width of a thumb, which varied based on regional standards. In 1959, an international agreement defined the inch as exactly 25.4 millimeters, ensuring consistency across countries using the imperial system.

Current Use

Inches are commonly used in countries like the United States, Canada, and the United Kingdom for:

• Construction and Carpentry: Measuring wood, pipes, and materials.

• Technology: Screen dimensions for TVs, monitors, and phones.

• Sports: Describing the diameter of wheels and athletic equipment.

Conversion Details

Conversion Formula and Factor

The relationship between centimeters and inches is straightforward:

• 1 centimeter = 0.3937 inches

• 1 inch = 2.54 centimeters

Formulas:

• To convert centimeters to inches:
  ( \text{inches} = \text{cm} \times 0.3937 )

• To convert inches to centimeters:
  ( \text{cm} = \text{inches} \times 2.54 )

Quick Reference Conversion Table

Step-by-Step Conversion Instructions

Converting Centimeters to Inches

1. Identify the length in centimeters. For example, 25 cm.

2. Multiply the value by the conversion factor (0.3937):
   ( 25 \times 0.3937 = 9.8425 )

3. The result is the equivalent measurement in inches: 9.84 inches (rounded to two decimal places).

Converting Inches to Centimeters

1. Identify the length in inches. For example, 15 inches.

2. Multiply the value by the conversion factor (2.54):
   ( 15 \times 2.54 = 38.1 )

3. The result is the equivalent measurement in centimeters: 38.1 cm.

Practical Examples

Example 1: Converting Centimeters to Inches

You are measuring a desk that is 120 cm long and want to express the length in inches.

• Step 1: Multiply the centimeters by 0.3937:
  ( 120 \times 0.3937 = 47.244 ).

• Result: The desk is approximately 47.24 inches long.

Example 2: Converting Inches to Centimeters

A TV screen is advertised as 55 inches. What is its size in centimeters?

• Step 1: Multiply the inches by 2.54:
  ( 55 \times 2.54 = 139.7 ).

• Result: The TV screen size is 139.7 cm.