Relation Between Inch and cm

Introduction

In our daily life, we come across various geometrical objects whose dimensions need to be measured for convenience. In this direction, there are various measuring instruments invented and used. In addition, the measured amount is expressed by various units. In this tutorial, we will discuss the units of measurement of length, metric system, feet system, various units, and their mutual conversion with solved examples.

Units of Measurement of Length

The measurement of length means to measure the distance between two end-points of the specific object. It is a skill that helps us measure the length of various objects. In geometry, we often draw various lengths of line segments. Various tools help to measure the length of an object. These are

• Ruler

• Yardsticks

• Metre tapes

• Feet/foot scale

We will discuss how to measure the length using a ruler.

• In the first step, we have to choose the measuring unit of length (cm or inches). Depending on the unit, we take the corresponding sides of the ruler (as shown in the figure).

• Place the zero position of the ruler beside the one endpoint of the object.

• Keep the ruler straight and mark the other end point of the object. For example, the stick's length is from 0 to 10 cm.

There are generally two categories of measuring length, standard units of measuring the length and non-standard units of measuring the length. The various units of these two categories are tabulated below.

Categories of measuring length	Units
Standard units	Millimetre Centimetre Decimetre Metre decametres Hectometres Kilometres
Non-standard units	Handspan Footspan Finger width Pace Cubit Thread or rope

Metric System

We have seen that there are various standard and non-standard units used for measuring length. For convenience, a common measuring system has been used worldwide. The common or universal measuring system is known as the metric system. The units included in the metric system are called SI units (International System of Units). Gabriel Mouton is the father of the metric system. The various units and their abbreviations are summarized below.

S.N.	Units	Abbreviation
1	Millimetre	mm
2	Centimetre	cm
3	Metre	m
4	Kilometre	km

Each unit of the metric system can be converted into one another. In this direction, there is a metric chart, which helps to find the conversion units. Let's see the conversion of one unit into another.

• 1 cm = 10 mm

• 1 mm = 0.1 cm

• 1 m = 100 cm

• 1 cm = 0.01 m

• 1 m = 1000 mm

• 1 km = 1000 m

• 1 m = 0.0001 m

Feet System

The length of the object can also be measured by feet if the length is long. There is a system called feet system (singular is foot) generally used in various regions of Greek, Rome, India, France, China, and the USA. However, the numeric value of the length in the case of the feet system varies from country to country. But still, the feet system can be expressed to the metric system using the following formula.

1 feet = 0.3048 m

Centimetres and Inches

Centimetres and inches are both measuring units of length. The centimetre is included in the metric system unit, whereas inches are included in the imperial system unit. The centimetre is the smallest measuring unit of length of the ruler. The rule is an example of a measuring tool that is marked with centimetre units. Inches are used to measure long length. Various measuring tapes are available in the market that use inches as the measuring unit. Centimetres and inches are both mutually convertible. That means we can evaluate the other if we know one value. The given instructions need to be followed to convert inches to centimetres.

• Multiply the value of inches by 2.54.

• Write cm beside the obtained value.

Conversion

Every unit of metric and imperial systems can be converted into one another. Let's see the conversion of one unit into another.

Measuring system	Conversion
Metric system	1 cm = 10 mm 1 mm = 0.1 cm 1 m = 100 cm 1 cm = 0.01 m 1 m = 1000 mm 1 km = 1000 m 1 m = 0.0001 m
Imperial system	1 feet = 12 inches 1 inches = 0.0833 feet
Metric to imperial system	1 cm = 0.3937 inches 1 m = 39.37 inches 1 m = 3.28 feet 1 km = 3280.84 feet
Imperial to Metric system	1 inch = 2.54 cm 1 foot = 30.48 cm 1 foot = 0.3048 m

Solved Examples

Example 1

A long cable wire of length 4550 inches needs to be manufactured. However, only 245 feet of wire is available. Determine the extra length (in feet) of wire is to be needed.

Solution

According to the question,

The length of the cable wire is = 4550 inches

As 1 inch = 0.0833 feet

4550 inch = 0.0833 × 4550 = 379.015 feet

The available length of cable is = 245 feet

Hence, the remaining length of cable wire needed = 379.015 - 245 = 134. 015 feet

∴ The extra length (in feet) of wire is 134.015 feet.

Example 2

Can a measuring instrument of length 400 mm, fit inside a geometry box of length 11.81 inches?

Solution

The length of the measuring instrument is = 400 mm

As 1 mm = 0.1 cm

400 mm = 0.1 × 400 = 40 cm

The length of the geometry box is = 11.81 inch

As 1 inch = 2.54 cm

11.81 inch = 2.54 × 11.81 = 30 cm

Since the length of the instrument is greater than the length of the box; therefore, the instrument cannot fit inside the geometry box.

Conclusion

The present tutorial gives a brief introduction about the relation between inch and cm. In addition, various measuring systems such as metric and foot systems have been briefly described. Moreover, some solved examples have been provided for better clarity of this concept. In conclusion, the present tutorial may be useful for understanding the relation between inch and cm.

FAQs

1. What is an imperial measuring system?

The imperial measurement system is commonly used to measure lengths in inches and yards.

2. What are the geometrical tools used to measure the length?

Various tools, such as a ruler, yardstick, metre sticks, etc., are used to measure length.

3. What is the SI unit of measurement of length?

The units included in the metric system are the SI units of length measurement. Those are cm, m, km, etc.

4. What is the smallest unit of measurement?

The smallest unit of measurement is millimetre.

5. What is the standard unit of measurement of length?

The standard unit of measurement of length is metre.