Centimeters (cm) and Inches (in) Conversion Calculator

An online cm and inches conversion calculator is presented along with conversion formulas, step-by-step examples, and practical word problems.

Common symbols and abbreviations:

Conversion Formula of Cm and Inches

By international agreement:

\[ 1 \text{ inch} = 2.54 \text{ centimeters} \] \[ 1 \text{ cm} = \left(\frac{1}{2.54}\right) \text{ inches} \approx 0.3937007874 \text{ inches} \]

Reference: NIST Reference Guidelines

Interactive Conversion Calculator

Enter the number of centimeters or inches to perform conversions with customizable decimal places.

cm         inches
inches         cm
Decimal Places

Examples of Conversion

Example 1

Convert \( 2.1 \, \text{cm} \) to inches and round the answer to 5 decimal places.

View Solution
\[ 2.1 \, \text{cm} = 2.1 \times 0.3937007874 \, \text{inches} \approx 0.82677165354 \, \text{inches} \]

Rounding to 5 decimal places gives:

\[ 2.1 \, \text{cm} \approx 0.82677 \, \text{inches} \]

Example 2

Convert \( 4.6 \, \text{inches} \) to cm and round the answer to the nearest cm.

View Solution
\[ 4.6 \, \text{inches} = 4.6 \times 2.54 \, \text{cm} = 11.684 \, \text{cm} \]

Rounding to the nearest whole centimeter (nearest unit) gives:

\[ 12 \, \text{cm} \]

Problems Involving Cm and Inches Conversions

Problem 1

A fence of length \( 600 \, \text{cm} \) is to be constructed using pallets of length \( 48 \, \text{in} \). How many pallets are needed?

View Solution

First, convert \( 600 \, \text{cm} \) into inches:

\[ 600 \, \text{cm} = 600 \times 0.3937007874 \, \text{in} = 236.22047 \, \text{in} \]

The number \( N \) of pallets required is:

\[ N = \dfrac{236.22 \, \text{in}}{48 \, \text{in}} = 4.92125 \]

Rounding up to the nearest higher whole number (since pallets come in whole units) gives:

\[ 5 \text{ pallets} \]

Problem 2

What is the area, in square centimeters, of a rectangular floor with dimensions \( 220 \, \text{in} \) by \( 150 \, \text{in} \)? Round the answer to the nearest square centimeter.

View Solution

Convert the dimensions of the floor to centimeters:

\[ L = 220 \, \text{in} = 220 \times 2.54 \, \text{cm} = 558.8 \, \text{cm} \] \[ W = 150 \, \text{in} = 150 \times 2.54 \, \text{cm} = 381 \, \text{cm} \]

The area \( A \) of the rectangular floor is given by \( A = L \times W \):

\[ A = 558.8 \, \text{cm} \times 381 \, \text{cm} = 212,902.8 \, \text{cm}^2 \]

Rounding to the nearest square centimeter (nearest unit):

\[ A = 212,903 \, \text{cm}^2 \]

Problem 3

Convert the volume \( V = 123.5 \, \text{cm}^3 \) into \( \text{in}^3 \) and round to the nearest hundredth of a cubic inch.

View Solution

By definition, \( 1 \, \text{cm}^3 = 1 \, \text{cm} \times 1 \, \text{cm} \times 1 \, \text{cm} \). Using the conversion factor \( 1 \, \text{cm} = 0.3937007874 \, \text{inches} \):

\[ 1 \, \text{cm}^3 = (0.3937007874 \, \text{in})^3 \approx 0.06102374409 \, \text{in}^3 \]

Therefore:

\[ V = 123.5 \times 0.06102374409 \, \text{in}^3 \approx 7.53643 \, \text{in}^3 \]

Rounding to the nearest hundredth (two decimal places):

\[ V = 7.54 \, \text{in}^3 \]

Problem 4

Convert the volume \( V = 2900 \, \text{in}^3 \) into \( \text{cm}^3 \) and round to the nearest \( \text{cm}^3 \).

View Solution

By definition, \( 1 \, \text{in}^3 = 1 \, \text{in} \times 1 \, \text{in} \times 1 \, \text{in} \). Using \( 1 \, \text{in} = 2.54 \, \text{cm} \):

\[ 1 \, \text{in}^3 = (2.54 \, \text{cm})^3 = 16.387064 \, \text{cm}^3 \]

Therefore:

\[ V = 2900 \times 16.387064 \, \text{cm}^3 = 47,522.4856 \, \text{cm}^3 \]

Rounding to the nearest cubic centimeter (nearest unit):

\[ V = 47,522 \, \text{cm}^3 \]

More References and Links