Measurement of Length – Definition, Units, Formula, Chart

Measuring length helps us figure out how long or tall something is with tools like rulers and measuring tapes. It’s a handy skill used everywhere—from the classroom to construction sites. Some of the Regularly used length measuring units are centimeters, millimeters, meters, inches, feet, yards, feet, etc. We use them to describe length in ways that make sense for different tasks. Understanding how to measure length is crucial not only for school projects but also in everyday tasks and various professions. Let’s explore the simple yet vital world of length measurement, a fundamental skill that shapes our understanding of the spaces and objects around us.

What is Length?

Units of Length Measurement

Measuring how long something is can be done in different ways. We can use centimeters, inches, and meters, or even our hands and feet. There are two kinds of measuring units we talk about: Standard length measuring units and non-standard length measuring units

Standard Units

Standard units are the official measurements used all around the world. These include centimeters (cm), meters (m), and kilometers (km) from the metric system, and inches (in), feet (ft), and miles (mi) from the imperial system. Using standard units means everyone understands the exact size you’re talking about, whether you’re measuring the length of a new sofa or the distance to your friend’s house. It’s like a common language for sizes and distances. Standard units can again be divided into two types: Imperial units and metric system units.

Imperial Units

The British Imperial System is a set of measurements that were officially adopted in Britain through the Weights and Measures Acts of 1824 and 1878. These acts standardized measurements like inches, feet, and yards. Here’s a look at some of the key Imperial units:

Metric System

The metric system simplifies measurements of length using units like kilometers, meters, and millimeters. The meter is the fundamental unit, and other measures are scaled by powers of ten from it.

• Kilometer (km) = 1000 meters.
• Hectometer (hm) = 100 meters.
• Decameter (dam) = 10 meters.
• Decimeter (dm) = 0.1 meters.
• Centimeter (cm) = 0.01 meters.
• Millimeter (mm) = 0.001 meters.

Non-Standard Units

Non-standard units are more informal and can be anything around us that we use to measure length. Common examples include using the width of your hand (handspan), the size of your foot (foot length), or even a pencil. These units are handy when you don’t have a ruler or tape measure nearby, or when precision isn’t critical. For instance, you might use your feet to walk off the size of a rug. While non-standard units can vary from person to person, they’re still useful for getting a rough idea of size or distance.

1. Handspan: Measured as the distance from the tip of the thumb to the tip of the little finger with the hand fully extended, Commonly used to measure the height of horses, one hand is equivalent to 4 inches (10.16 cm). This measure comes from using the width of an adult’s hand (including the thumb) as a rough gauge.
2. Footspan: The foot-span is described as the length from the tip of the toe to the back of the heel. A casual unit based on an individual’s step. While it varies, an adult’s step is roughly estimated to be 2.5 to 3 feet long. It’s often used for rough distance estimations.
3. Cubit: An ancient measurement based on the length of a person’s forearm from the elbow to the tip of the middle finger, typically around 18 inches (45 cm). It was used in many ancient civilizations for construction and is mentioned in historical documents.
4. Fathom: Originally used for measuring the depth of water, one fathom equals 6 feet (1.83 meters) or the distance from one hand to the other with arms fully stretched out to the sides.
5. Pace: A measure of distance equivalent to a full stride, from the point where one foot lifts off the ground to the point where it lands again, around 5 feet (1.5 meters). This unit is often used in walking or hiking to estimate distances.
6. Rod (or Pole or Perch): An older unit of length used mainly in land measurement, equal to 5.5 yards or 16.5 feet (5.029 meters). This measurement was commonly used in surveying land for agricultural and construction purposes.

SI Unit of Length

The SI (International System of Units) unit of length is the meter (symbol: m). The meter is defined as the distance light travels in a vacuum in 1/299,792,458 of a second. The meter is the base unit of length.

• 1 m = 100 cm
• 1 m = 1000 mm
• 1 m = 0.001 km
• 1 m = 39.37 inches
• 1 m = 1.09361 yards
• 1 m = 3.28 feet

Tools used for Measurement of Length

Measurement of length is fundamental in various fields, such as construction, engineering, tailoring, and everyday activities. Understanding the tools used for measuring length helps in selecting the appropriate instrument based on accuracy, unit of measurement, and the object or distance being measured. Below, we explore some commonly used tools for length measurement, highlighting their applications and features.

1. Ruler

A ruler is one of the most basic and widely used tools for measuring length. Typically made of wood, metal, or plastic, rulers are available in various sizes, with lengths of 6 inches (15 cm) and 12 inches (30 cm) being the most common. They are ideal for measuring short distances and are commonly used in schools, offices, and by DIY enthusiasts.

2. Tape Measure

A tape measure is a flexible ruler used to measure size or distance. It consists of a ribbon of cloth, plastic, fibre glass, or metal strip with linear-measurement markings. Tape measures are commonly used in construction, architecture, and sewing. They are versatile and can measure round or curved surfaces, making them indispensable for tailors and carpenters.

3. Calipers

Calipers are precision tools used to measure the distance between two opposite sides of an object. There are several types of calipers, including vernier, digital, and dial calipers, each providing different levels of accuracy. Calipers are essential in mechanical engineering, metalworking, and other fields where precise measurements are crucial.

4. Micrometer

A micrometer, also known as a micrometer screw gauge, is a device used for precision measurement of small distances. It offers higher accuracy than calipers, with the ability to measure thickness, diameters, and depths of objects. Micrometers are widely used in mechanical engineering, machining, and scientific research.

5. Laser Measure

Laser measures are advanced tools that use laser technology to measure distances, areas, and volumes. They are highly accurate and can measure long distances with ease. Laser measures are beneficial in construction, real estate, and landscaping where traditional measuring tools may not be practical.

6. Yardstick

A yardstick is a long, flat measuring stick, typically 36 inches (1 yard) in length. It is used for measuring lengths and drawing straight lines on large surfaces. Yardsticks are common in tailoring, woodworking, and educational settings for measuring fabric, wood, and various project materials.

7. Measuring Wheel

A measuring wheel, also known as a surveyor’s wheel, is used for measuring long distances by rolling it along the ground and counting the number of rotations, which corresponds to the distance traveled. It is commonly used in surveying, landscaping, and by law enforcement for accident scene measurements.

Measurement of Length Formula

Converting within the Metric System

• From millimeters to centimeters: divide by 10 (because 10mm = 1cm).
• From centimeters to meters: divide by 100 (because 100cm = 1m).
• From meters to kilometers: divide by 1,000 (because 1,000m = 1km).

Imperial System

• From inches to feet: divide by 12 (because 12in = 1ft).
• From feet to yards: divide by 3 (because 3ft = 1yd).
• From yards to miles: divide by 1,760 (because 1,760yd = 1mi).

How to Measure Length?

1. Pick the Right Measuring Tool: Choose a ruler for small items, a tape measure for larger or flexible things, and a laser measure for big spaces.
2. Decide on Units: Think about if you need to measure in inches, feet, or centimeters. Make sure your tool has these units.
3. Get Ready to Measure: Put the item flat. If it’s something like fabric, smooth it out so it’s straight.
4. Line Up the Tool: Start measuring by placing the zero end of your tool at one end of the item.
5. Measure the Length: Pull your tool to the other end of the item. For circles, go straight across the middle.
6. Read and Note Down: Look at where the tool stops at the end of the item and write down the number you see, along with the unit (like inches or centimeters).

Measurement of Length Chart

FAQs

What goes first length or width?

Typically, length is mentioned before width when describing dimensions, adhering to the convention of “length by width” for measurements of objects or areas.

What is the actual size of 1 inch to cm?

One inch is exactly equal to 2.54 centimeters. This conversion is fundamental in measurements, allowing for precise transitions between the imperial and metric systems.

What is 1 centimeter measurement?

A centimeter is a unit of length in the metric system, equal to one hundredth of a meter. It’s a common measure for everyday objects and distances.