‘Mass’ and ‘density’ are two terms that are used interchangeably in most cases. These two terms imply entirely different meanings and help quantify matter.
They are related to each other in terms of formula but mean different things.
Key Takeaways
- Mass measures the amount of matter in an object, expressed in units such as grams or kilograms.
- Density is the ratio of an object’s mass to its volume, representing how compactly the mass is distributed within the object. It is measured in units like grams per cubic centimeter or kilograms per cubic meter.
- Both mass and density are fundamental properties of matter, but they describe different aspects: mass quantifies the amount of matter, while density describes its distribution within a given volume.
Mass vs. Density
Mass, in the realm of physics, is the measure of the total amount of matter present in an object, and it is measured in units of kilograms. Density is the measure of how much mass is contained within a specific unit of volume. It is expressed in units such as kilograms per cubic meter.

Mass is the quantity of matter present in any substance or thing that can be expressed in units such as kilograms or grams.
On the other hand, density is a different concept that defines how much mass is present in any substance concerning its volume. This should be clearly understood that the mass of an object remains the same and is never influenced by the force of gravity.
This should be kept in mind that the mass of any object is not similar to the weight of the thing.
Comparison Table
Parameters of comparison | Mass | Density |
---|---|---|
Definition | Mass is the total amount of matter present in any object. | Density is the total mass of any object concerning its volume. |
Formula | The mass of any object can be depicted by- Mass= density*volume | The density of any object can be depicted by- Density= mass/ volume |
SI unit | It is expressed by the unit grams or kilograms. | It is expressed as gm/cm3 or kg/m3 |
State of matter | The mass of any object doesn’t define the shape of the case. | The density of any object helps depict the state of matter. |
Characteristic | Mass is the measure of inertia. | Density is used to define the compactness of any object. |
What is Mass?
Mass is the property of any substance that depicts the total amount of matter present in that substance. The critical aspect of mass is that it remains constant everywhere because it is not affected by the force of gravity. For example, if a ball has a mass of 2 kg on earth, then its mass on the moon will also remain the same. Even though the force of gravity changes but the mass never changes.
Mass is also the measure of inertia of any object, which means the heavier the body, the more it will resist movement. It broadly represents the matter present in anybody.
It is expressed by the unit kilograms or grams. Mass is a scalar quantity because the direction of the object does not determine it.
The mass of any object is extrinsic property because it denotes the amount of matter present in the substance.
It should also be noted that mass and weight are different. Weight changes with gravitational force, but the group doesn’t change.
What is Density?
Density is the property of any substance that determines the object’s total mass concerning its volume. It is the most used concept in science that defines the degree of compactness in any sense.
Density depicts the state of matter, denoting whether something is solid, liquid, or gas.
To know the density of any object, we have to divide the object’s mass by the volume it occupies. Indeed, the thickness can also be called the space occupied by any entity.
The object’s density remains the same no matter its shape or size. It changes with different temperatures and pressure.
Most of the time, density is responsible for the sinking and floating of objects. The objects with less density float, whereas those with higher density sink.
For Example, a wood log floats in water, whereas an iron nail sinks.
The density of any substance is the intrinsic property because it doesn’t depend on the quantity of the matter contained.
Main Differences Between Mass and Density
- Mass is the total amount of matter in any substance, whereas density is the total mass in any object concerning its volume.
- The object’s mass changes shape and size, whereas the density of any object remains the same irrespective of its shape and size.
- Mass measures inertia in any object, whereas density defines the degree of compactness in any object.
- The mass of any object is given by density × volume, whereas the density of any object is given by mass ÷ volume.
- The SI units that represent the mass of any object are kilograms and grams, whereas those of density is kg/m3 or gm/cm3.
