Relation Between Inch and cm

1 Meter to CM

A meter is the base unit of length and distance in the International System of Units (SI).

                                      1m = 100cm

A centimeter is a unit of length in the International System of Units (SI), the current form of the metric system. 

                                      1cm = 1/100m

1 Foot in CM

A foot is a non-SI unit of distance or length, measuring around a third of a meter. One yard consists of three feet, and twelve inches make a foot.

                                         1 foot = 30.48 cm


A centimeter is a unit of length that is equal to one-hundredth of a metre.

                                      1 cm = 0.0328084 foot

CM to Inches to Feet

                                 1cm =  0.0328 feet   or     0.3937 inches

The relation between inch and centimeter (cm) is one of the most used calculations in our daily life. But to understand the relation between inch and centimeter (cm), one has to know the definition of inch and centimeter (cm).

Both inch and centimeter (cm) are the systems used to measure sets of length, weight, capacity temperature, speed, etc.

Conversion of Units

In Mathematics, the conversion is one of the most important parts while solving problems with a different system of measurement to carry out the required calculations.  

For example: In a question, you are asked to find the perimeter of a rectangle in inches, but the breadth given is in meters and the height in centimeters (cm). First, you have to convert meter (m) in centimeter (cm) then solve the perimeter when you find the value of perimeter, and you have to change the answer into inches using the relation between centimeter (cm) and inch. Conversion of units is very easy, but it tends to be confusing because of the operation of numbers to multiply and divide.

Why and How to Convert Units?

We need to convert units depending on the situation. For example height of a person is measured in centimeter (cm), while distance covered by a vehicle in kilometer (km), thickness of stainless steel in millimeter (mm) distance between two ends of a room in meter (m), biceps and chest in inches.


Thus, to convert any of these units, we have to understand the concept of the relation between those units.


So, in this article, we are going to understand the relation between inches and centimeters (cm).

Inch 

Inch is a system used to measure quantities like length, weight, capacity, temperature, etc. based on the English system of measurement. Inch is defined as the unit of measurement of length denoted by 'in' and represented by the symbol ' " '. Two half inches or four-quarter inches are combined to form one whole of an inch.

For example, 10 inches can be written as '4 in' or represented by '4" '. 

Representation of Inch


  • 1" = One inch

  • ½" = One half of an inch

  • ¼" = One-quarter of an inch

  • ⅛" = One-eighth of an inch

  • 1/16" = One-sixteenth of an inch

Centimeter (cm)

Centimeter is used to measure length in the metric system. Centimeter is 1/100th of a meter which means 

       1 meter (m) = 100 centimeter (cm)

                             Or

       1 centimeter (cm) = 0.01 meter (m)

and 1 centimeter (cm) is also equal to 10 millimeter (mm).

'CM' is abbreviated at the place of 'centimeter '. Also when 1 centimeter (cm) is converted into inches or is equal to 0.3937 inches. 

Conversion from a centimeter (cm) to Inches

Conversion from Centimeter (cm) to Inches


Centimeters (cm)

Inches (”)

0.0396875 cm

1/64 in

0.0793750 cm

1/32 in

0.15875 cm

1/16 in

0.3175 cm

1/ 8 in

0.635 cm

1/ 4 in

1.27 cm

1 /2 in

2.54 cm

1 in

5.08 cm

2 in

7.62 cm

3 in

10.16 cm

4 in

12.70 cm

5 in

15.24 cm

6 in

17.78 cm

7 in

20.32 cm

8 in

22.86 cm

9 in

25.40 cm

10 in


Questions:

Question 1.   Convert 12 cm into inches.

        Ans.     To convert 12 cm to inches, we need to divide the amount by 2.54.

                12 ÷ 2.54 = 4.724 (to 3dp)

      So, 12 cm = 4.724 inches.


Question 2. A three feet tall person is 36 inches tall. Calculate how many centimeters tall a three feet person.

Ans.        We know that,

                      36 in = 36 in (2.54 cm/ 1 in)

     Now cancel out inches,

          We get

                  36 in = 36 x 2.54

                  36 in = 91.44 cm

Therefore, a three feet person is 91.44 centimeters tall.


Question 3.  Given figure depicts an archery target marked with its five scoring areas from the center outwards as Yellow, Orange, Purple, Brown, and Grey. The diameter of the region representing Yellow score is 21 cm, and each of the other bands is 10.5 cm wide then find the area of each of the five scoring regions.  


     Ans.   Diametre of yellow circle = 21cm

           So, Radius of yellow = Diametre/2 = 21/2 cm = 10.5 cm 

            Now,

                Area of yellow = πrGOLD2

                                     = 22/7 ×10.5 × 10.5

                                     =   346.5 cm2   

  Now, 

   Radius of orange = Radius of yellow + width of band 

                            = 10.5 + 10.5

                            =  21 cm

     Area of (orange + yellow) =  πrRED2

                                        =  22/7 × 21 × 21

                                      =   1386 cm2

     Area of orange = Area of (orange + yellow) - Area of yellow

                         = 1386 - 346.5

                         = 1039.5 cm

     Radius of purple = Radius of orange + Width of band

                            = 21 + 10.5

                            = 31.5 cm

    Area of (yellow + orange + purple) = πr2

                           = 22/7 × (31.5)2

                           = 22/7 × 31.5 × 31.5

                           = 22/7 × 4.5 × 31.5

                           = 3118.5 cm2

     Area of purple = Area of (orange + yellow + purple) - Area of (orange + yellow)

                          = 3118.5 - 1386

                          = 1732.5 cm2

   Radius of brown = Radius of purple + Width of band

                            =  31.5 + 10.5

                            =  42 cm

    Area of (yellow + orange + purple + brown) = πr2

                              =   22/7 × (42)2

                            =   22/7 × 42 × 42

                            =   5544 cm  

   Area of brown portion =  Area of (yellow + orange + purple + brown) - Area of (yellow + orange + purple)

                            =   5544 - 3118.5

                            =   2425.5 cm2

   Radius of grey = Radius of brown + width of band 

                             =   42 + 10.5

                             =    52.5 cm2

   Area of grey portion = Area of (yellow + orange + purple + brown + grey) - Area of (yellow + orange + purple + brown)

                             =   8662.5 - 5544

                             = 3118.5 cm2


FAQ (Frequently Asked Questions)

1. What size is an inch?

 2.5 cm is a rough measurement of an inch. It is measured as the thumb knuckle to top of the thumb of a person.

2. What is 1cm equal to in inches?

1cm measures 0.3937 inches in decimal and 25/64 inches in fraction.