Measurement is a way to quantify an attribute of an object concerning known standards in numerical values. The attribute of the host/object can be length, weight, height etc.

There are different units of measurement followed across the world. The International System of Units (SI) has become the commonly accepted measurement standard.

There are seven fundamental units defined under the SI system. The meter is the standard unit of measurement for both length and height. It is denoted by the symbol ‘m’.

Though they share the same unit for measurement, length and height, they have different meanings and unique definitions.

## Key Takeaways

- Length and height are two different measures of distance. Length measures the distance between two points in a straight line. Height, on the other hand, is the measurement of the distance between the base and the highest point of an object.
- Length is measured horizontally, while height is measured vertically. For example, the length of a bookshelf would be the distance from one end to the other along the top surface, while the height would be the distance from the floor to the top shelf.
- Length is used to measure the size of objects in two dimensions, while height is used to measure the size of objects in three dimensions. Length can be used to compare the size of two side-by-side objects, while height is used to compare the size of objects stacked on top of each other.

**Length vs Height**

The length refers to the longest dimension of an object, measured from one end to the other in a straight line; it is commonly used to describe horizontal distance. On the other hand, height refers to an object’s vertical dimension, measured in a straight line from the bottom to the top of the object.

For instance, let us consider a cube occupying some space. Measuring the cube in the horizontal plane from one point to another represents the length.

When the same cube is measured from one point to another in the vertical plane, it denotes the height of the cube.

**Comparison Table**

Parameter of Comparison | Length | Height |
---|---|---|

Definition | Refers measuring an object in the same plane from one edge/point to another | Refers to measuring an object from top to bottom or vice-versa |

The direction in which it is measured | Horizontal direction | Vertical direction |

What does it denote | Tells us the extension or how long the target/object is | Tells us the elevation/altitude of the target/object is |

Usage in Co-ordinate geometry | Generally, the length is considered along the X-axis | Height is considered along the y-axis |

Dimension | Measured for one, two- and three-dimensional object | Height is an attribute of a three-dimensional object. |

**What is Length?**

Length can be defined as an extension of an object measured from one point to another in the horizontal direction. Measurement in X-axis is the general representation of length in Coordinate geometry.

The unit of length depends on the measurement standard followed. In the case of the SI system, the unit is the meter (denoted as ‘m’). In the British or Imperial system, it is called the yard.

One yard equals 0.9144 meters. When mentioning the size of a three-dimension object, the length is always written first.

Generally speaking, the distance we travel falls under the length category. But the units vary depending on the target we measure. For instance, the astronomical unit(au) is used while measuring distance in outer space.

Dalton signifies the sub-atomic distance. Length is used synonymously with distance in the field of science. Though width and breadth are measured horizontally, the longest represents the length.

**What is Height?**

Height is another attribute of an object that denotes the target object’s altitude from a given reference. It is measured from the ground level/base to the top of the object.

Measurement in Y-axis is the nominal representation of height in Cartesian Co-ordinate geometry.

The unit of height matches that of length. Meter, yard, inches, foot etc., are also used to denote height. How the attribute is measured signifies whether the quantity is length or height.

Height always denotes the tallness of the target/object.

For example, it is incorrect to say the length of the tallest peak rather than the height of the tallest peak.

Height is important to a person’s health condition as it is one of the parameters in calculating BMI (Body Mass Index). Studying human height is one of the core areas of interest in anthropometry.

Anthropometry assumes significance as it provides vital information while deciding the ergonomics of any object. It is considered as one of the important factors in industrial design as well.

**Main Differences Between Length and Height**

- Length indicates how long the target/object is, whereas height indicates how tall the target/object is.
- Distance travelled is always attributed to length, while altitude is to height.
- The direction for measuring length is horizontal, and the direction for measuring height is aligned to the vertical direction.
- X-axis ascertains length, and Y-axis indicates the height in mathematics (Cartesian Co-ordinates)
- One- and two-dimensional objects possess length and height and are considered only in three-dimensional space. Height is unique to three-dimension objects.
- An example of a one-dimension quantity can be a line with only one attribute, i.e. the length or the distance from one point to another. An example of a three-dimension quantity is a cuboid made up of three different attributes, i.e., length, breadth and height.
- Height (elevation) is an important parameter in aviation. Travelling at a specific elevation becomes an essential part of landing and manoeuvre for pilots. Not maintaining the desired elevation could even lead to disaster.
- Length signifies importance while calculating the distance from one place to another. The distance we travel is either mentioned in metres or kilometres. The centimetre is used while measuring a smaller quantity.
- While considering an object, the long facet is always considered as the object’s length. And the face of the object in normal orientation is denoted by height (measured upwards)
- In three-dimensional space, height is always perpendicular to the plane formed due to a combination of width and length.

**References**

Last Updated : 11 June, 2023

Emma Smith holds an MA degree in English from Irvine Valley College. She has been a Journalist since 2002, writing articles on the English language, Sports, and Law. Read more about me on her bio page.