The 7 Base Units of Measurement

The scientific study of measurement is the basis of Metrics SI Units. There is a standard measurement used internationally to define various elements affected by time and distance. There are negligible differences between measurements by the British, American, Australian, and other nations but mostly it is based on a name. It is important to understand how these measurements work and how they differ depending on your location. Accuracy is based on the integration of a relating formula.

A unit of measurement is a standard of measurement for every quantity based on a definite law. While quantity varies, the standard helps in defining the changing values. Different professional fields use different measurement standards; like the definition of units of measurement in science, engineering, and medicine differ with theories of measurement in social sciences. Physical quantities are measured by units of measurement defined by laws in physics and metrology.

Here are the 7 base SI units of measurement


Sandglass was the original unit of measuring time where candles and lamps were used. With time, clocks became a reliable means of measuring periods. Clocks are more accurate, which also became the technique to measure sandglasses. Today, it is used to determine lecture time and travel time.

The smallest unit of measuring time is seconds. It is a measure of periods based on radiation relating to a corresponding change from one hyperfine level to a ground state. The second unit of measuring time is based on cesium 133 atom. 13th CGPM (1967/68, Resolution 1; CR, 103) is the formula used to define cesium atom when it is at rest. The standard temperature at this point is O K.

A day is defined by 24 hours where every hour is 60 minutes and every minute is divided into 60 seconds. This is the justification of the unit of measuring time. It is an international standard.


Mass is linked to the size of a physical body. The unit of measurement for mass is then related to resistance level when force is applied to a body. The acceleration level and force applied to the body demonstrates the strength. In most cases, a physical body on the surface of the earth is defined by gravitational force. Everybody is attracted by a natural force pulling it to the ground.

The unit of measuring mass is kilogram. Kg is equated to the mass of a specific prototype based on kilogram. Kg is related to cubic meter based on the state of matter. Whether it is in liquid or solid, the mass can be determined with kilograms.


The extension of an object is the basic definition of length. The dimensions of an extension are determined by quantity based on distance. It can also be determined as a measure of an object by the same dimension without any form of displacement. The main difference between length and height is the direction of the dimension. Length is determined by displacement distance from one side to another. The right angles to respective sides determine the length of an object. Width or vertical extent of an object does not influence the length.

Length is measured in meters denoted by (m). Meter is defined as the path travelled by light in a vacuum based on time. The distance from one side to another is based on distance from the equator to the North Pole, which is influenced by the circumference of the earth.

Electric current

Current is basically the flow of electric current from source to the bulb or any other point of contact. As long as electric charge is dispatched, it has to move to any point of contact, the electric power between the source and the point of contact is referred to as electric current. The charge is carried by electrons in an electric wire. Electric current can also flow through ions, which are the primary components of an electrolyte. Ionized gas can also be a carrier for electrons hence related to electric current.

Electric current is measured by ampere denoted by (A). ampere is defined as a constant current that maintains two conductors in parallel and indefinite length. Ampere is not limited to circular cross-sections; it is defined with 1 meter apart in a vacuum. Every meter produces 2×10−7. Originally, the definition of the ampere was based on electrochemical currents based on milligrams of silver running through the cables every second.

Thermodynamic temperature

Thermodynamics is a specific field of study that is defined by temperature as one of its key principals. It is the absolute measure of temperature based on the movement of physical objects and how they interact with forces of nature. Thermodynamic temperature is considered the null point of temperature because of its blend of energy and how it affects temperature. The catch with this absolute measure is a constant change of the body that helps in determining a level point for temperature.

Thermodynamic temperature is measured in Kelvin denoted by (K). The unit of measurement is a percentage of the triple point of water. In this case, water s assumed to have isotopic composition, which is defined by specific ratios. Kelvin increase is based on changes in Celsius state but still maintain the scale of thermodynamic measurement.

Amount of substance

Amount of substance can also be referred to as chemical amount. It is a measure of quantity based on the size of atoms, electrons, molecules among other particles. It is considered to be proportionally constant to an inverse of Avogadro constant.

Amount of substance is measured by mole (mol) where elementary quantities have to be specified as a group of particles. The atoms that contain a specific amount of carbon have to be at rest on the ground. Mole is defined by the weight of an atom divided by a constant of molar mass.

Luminous intensity

This is the measure of wavelength from a specific light source based on the direction of every unit of light. It is measured by candela, which is entirely based on the direction of the light source. Luminous intensity is measured basing on hertz and radiant intensity. Candela is defined by the light from a burning candle.