Difference Between Mass and Weight

Sl. No.

Differentiating Property

Mass

Weight

1

Definition

  • Mass is simply the measure of the amount of matter in a body.
  • Weight is the measure of the amount of force acting on a mass due to acceleration due to gravity.

2

Denotation

  • Mass is denoted by “M”.
  • Weight is denoted by “W”.

3

Formula

  • Mass is always constant for a body and there are several formulas to calculate mass.
  • One way to calculate mass is:

Mass = volume × density

  • Weight is the measure of the gravitational force acting on a body.
  • Weight can be calculated from the following formula:

Weight = mass × acceleration due to gravity

4

Quantity Type

  • Mass is a base quantity.
  • Mass only has magnitude and so, it a scalar quantity.
  • Weight is a derived quantity.
  • Weight has both magnitude and direction (towards the center of gravity) and so, it is a vector quantity.

5

Unit of Measurement

  • The SI unit of mass is Kilogram (Kg).
  • The SI unit of weight is Newton (N).

6

Gravitational Effect

  • Mass does not depend upon gravity and is constant everywhere.
  • Mass can never be zero.
  • Weight is dependent on the gravity and so, it varies from place to place.
  • Weight can be zero where there is no gravity (like space).

7

Measuring Instrument

  • Mass can be easily measured using any ordinary balance like beam balance, lever balance, pan balance, etc.
  • Weight can be measured by a spring balance or by using its formula.