# Mass vs. Weight — What's the Difference?

Edited by Tayyaba Rehman — By Fiza Rafique — Updated on November 2, 2023
Mass is the amount of matter in an object; weight is the force exerted by gravity on that mass.

## Key Differences

Mass is a measure of how much matter an object contains, independent of gravity, and is measured in kilograms or grams. Weight, on the other hand, is the force exerted by gravity on that mass and varies with the strength of the gravitational pull.
While mass is an intrinsic property of an object and does not change whether you’re on Earth, the Moon, or in space, weight changes with the location due to differences in gravitational pull. Thus, an object’s weight is mass times the acceleration due to gravity.
Mass is conserved in closed systems, implying that it remains constant regardless of position and environment. Weight, conversely, can change without any alteration in mass, as seen during spaceflight or on different celestial bodies.
In scientific equations, mass is represented by 'm', and is a scalar quantity, which means it only has magnitude. Weight, denoted as 'W', is a vector, which means it has both magnitude and direction; the direction is always towards the center of the gravitating body.

## Comparison Chart

### Definition

Amount of matter in an object
Force due to gravity on an object

### Measurement Unit

Kilograms (kg), grams (g)
Newtons (N), pounds (lbs)

### Dependency

Constant, does not depend on location
Depends on gravitational strength

M
W

### Nature

Scalar quantity (has only magnitude)
Vector quantity (has magnitude and direction)

## Compare with Definitions

#### Mass

A measure of the amount of matter in an object.
The mass of the apple is 100 grams.

#### Weight

The gravitational force exerted on an object's mass.
The weight of her luggage exceeded the airline's limit.

#### Mass

Invariant to the object's location.
The astronaut's mass is the same on Earth and the Moon.

#### Weight

Changes with the strength of the gravitational field.
His weight on the Moon is one-sixth his weight on Earth.

#### Mass

Used to calculate weight (mass x gravity).
A mass of 20 kg results in a weight of about 196 Newtons on Earth.

#### Weight

Measured using scales.
The scale showed her weight as 150 pounds.

#### Mass

Mass is both a property of a physical body and a measure of its resistance to acceleration (rate of change of velocity with respect to time) when a net force is applied. An object's mass also determines the strength of its gravitational attraction to other bodies.

#### Weight

Can vary without a change in mass.
The astronaut's weight is less in orbit than on Earth.

#### Mass

The celebration of the Christian Eucharist, especially in the Roman Catholic Church
We went to Mass

#### Weight

In science and engineering, the weight of an object is the force acting on the object due to gravity.Some standard textbooks define weight as a vector quantity, the gravitational force acting on the object. Others define weight as a scalar quantity, the magnitude of the gravitational force.

#### Mass

Involving or affecting large numbers of people or things
A mass exodus of refugees
The film has mass appeal

#### Weight

A measure of the heaviness of an object
A contest to guess the weight of a pig.

#### Mass

Assemble or cause to assemble into a single body or mass
Both countries began massing troops in the region
Clouds massed heavily on the horizon

#### Weight

The force with which a body is attracted to Earth or another celestial body, equal to the product of the object's mass and the acceleration of gravity.

#### Mass

Public celebration of the Eucharist in the Roman Catholic Church and some Protestant churches.

#### Weight

A unit measure of gravitational force
A table of weights and measures.

#### Mass

The sacrament of the Eucharist.

#### Weight

A system of such measures
Avoirdupois weight.
Troy weight.

#### Mass

A musical setting of certain parts of the Mass, especially the Kyrie, Gloria, Credo, Sanctus, and Agnus Dei.

#### Weight

A metallic solid used as a standard of comparison in weighing.

#### Mass

A unified body of matter with no specific shape
A mass of clay.

#### Weight

An object used to hold something else down.

#### Mass

A grouping of individual parts or elements that compose a unified body of unspecified size or quantity
"Take mankind in mass, and for the most part, they seem a mob of unnecessary duplicates" (Herman Melville).

#### Weight

A counterbalance in a machine.

#### Mass

A large but nonspecific amount or number
A mass of bruises.

#### Weight

(Sports) A heavy object, such as a dumbbell, lifted for exercise or in athletic competition.

#### Mass

A lump or aggregate of coherent material
A cancerous mass.

#### Weight

Excessive fat; corpulence
Exercising in order to lose weight.

#### Mass

The principal part; the majority
The mass of the continent.

#### Weight

(Statistics) A factor assigned to a number in a computation, as in determining an average, to increase or decrease the number's effect on the computation, reflecting its importance.

#### Mass

The physical volume or bulk of a solid body.

#### Weight

Oppressiveness; pressure
The weight of responsibilities.

#### Mass

Abbr. m(Physics) A property of matter equal to the measure of the amount of matter contained in or constituting a physical body that partly determines the body's resistance to changes in the speed or direction of its motion. The mass of an object is not dependent on gravity and therefore is different from but proportional to its weight.

#### Weight

The greater part; preponderance
The weight of the evidence is against the defendant.

#### Mass

An area of unified light, shade, or color in a painting.

#### Weight

Influence, importance, or authority
Her approval carried great weight.

#### Mass

(Pharmacology) A thick, pasty mixture containing drugs from which pills are formed.

#### Weight

Ponderous quality
The weight of the speaker's words.

#### Mass

Masses The body of common people or people of low socioeconomic status
"Give me your tired, your poor, / Your huddled masses yearning to breathe free" (Emma Lazarus).

#### Weight

(Sports) A classification according to comparative lightness or heaviness. Often used in combination
A heavyweight boxer.

#### Mass

To gather or be gathered into a mass.

#### Weight

The heaviness or thickness of a fabric in relation to a particular season or use. Often used in combination
A summerweight jacket.

#### Mass

Of, relating to, characteristic of, directed at, or attended by a large number of people
Mass education.
Mass communication.

#### Weight

A measure of the relative thickness of yarn.

#### Mass

Done or carried out on a large scale
Mass production.

#### Weight

To make heavy or heavier
Our backpacks were weighted down with food and other essentials.

#### Mass

Total; complete
The mass result is impressive.

#### Weight

To cause to feel concerned, sad, or preoccupied; burden or oppress
He was weighted with guilt.

#### Mass

(physical) Matter, material.

#### Weight

To increase the weight or body of (fabrics) by treating with chemicals.

#### Mass

A quantity of matter cohering together so as to make one body, or an aggregation of particles or things which collectively make one body or quantity, usually of considerable size.

#### Weight

(Statistics) To assign weights or a weight to.

#### Mass

(obsolete) Precious metal, especially gold or silver.

#### Weight

To cause to have a slant or bias
Weighted the rules in favor of homeowners.

#### Mass

(physics) The quantity of matter which a body contains, irrespective of its bulk or volume. It is one of four fundamental properties of matter. SI unit of mass: kilogram.

#### Weight

(Sports) To assign to (a horse) the weight it must carry as a handicap in a race.

#### Mass

(pharmaceutical drug) A medicinal substance made into a cohesive, homogeneous lump, of consistency suitable for making pills; as, blue mass.

#### Weight

The force on an object due to the gravitational attraction between it and the Earth (or whatever astronomical object it is primarily influenced by).

#### Mass

(medicine) A palpable or visible abnormal globular structure; a tumor.

#### Weight

An object used to make something heavier.

#### Mass

(bodybuilding) Excess body weight, especially in the form of muscle hypertrophy.

#### Weight

A standardized block of metal used in a balance to measure the mass of another object.

#### Mass

(proscribed) weight

#### Weight

Importance or influence.

#### Mass

A large quantity; a sum.

#### Weight

(weightlifting) An object, such as a weight plate or barbell, used for strength training.
He's working out with weights.

#### Mass

Bulk; magnitude; body; size.

#### Weight

(lubricants) viscosity rating.

#### Mass

The principal part; the main body.

#### Weight

(physics) Mass (atomic weight, molecular weight, etc.) in restricted circumstances

#### Mass

A large body of individuals, especially persons.
The mass of spectators didn't see the infraction on the field.
A mass of ships converged on the beaches of Dunkirk.

#### Weight

Synonym of mass}} {{qualifier

#### Mass

(in the plural) The lower classes of persons.
The masses are revolting.

#### Weight

(measurement) Mass (net weight, troy weight, carat weight, etc.).

#### Mass

(Christianity) The Eucharist, now especially in Roman Catholicism.

#### Weight

(statistics) A variable which multiplies a value for ease of statistical manipulation.

#### Mass

(Christianity) Celebration of the Eucharist.

#### Weight

(topology) The smallest cardinality of a base.

#### Mass

The sacrament of the Eucharist.

#### Weight

(typography) The boldness of a font; the relative thickness of its strokes.

#### Mass

A musical setting of parts of the mass.

#### Weight

(visual art) The relative thickness of a drawn rule or painted brushstroke, line weight.

#### Mass

(transitive) To form or collect into a mass; to form into a collective body; to bring together into masses; to assemble.

#### Weight

(visual art) The illusion of mass.

#### Mass

(intransitive) To assemble in a mass

#### Weight

(visual art) The thickness and opacity of paint.

#### Mass

To celebrate mass.

#### Weight

Pressure; burden.
The weight of care or business

#### Mass

Involving a mass of things; concerning a large quantity or number.
There is evidence of mass extinctions in the distant past.

#### Weight

The resistance against which a machine acts, as opposed to the power which moves it.

#### Mass

Involving a mass of people; of, for, or by the masses.
Mass unemployment resulted from the financial collapse.

#### Weight

Shipments of (often illegal) drugs.
He was pushing weight.

#### Mass

The sacrifice in the sacrament of the Eucharist, or the consecration and oblation of the host.

#### Weight

One pound of drugs, especially cannabis.

#### Mass

The portions of the Mass usually set to music, considered as a musical composition; - namely, the Kyrie, the Gloria, the Credo, the Sanctus, and the Agnus Dei, besides sometimes an Offertory and the Benedictus.

Money.

#### Mass

A quantity of matter cohering together so as to make one body, or an aggregation of particles or things which collectively make one body or quantity, usually of considerable size; as, a mass of ore, metal, sand, or water.
If it were not for these principles, the bodies of the earth, planets, comets, sun, and all things in them, would grow cold and freeze, and become inactive masses.
A deep mass of continual sea is slower stirredTo rage.

Weight class

#### Mass

A medicinal substance made into a cohesive, homogeneous lump, of consistency suitable for making pills; as, blue mass.

#### Weight

(transitive) To add weight to something; to make something heavier.

#### Mass

A large quantity; a sum.
All the mass of gold that comes into Spain.
He had spent a huge mass of treasure.

#### Weight

To load (fabrics) with barite, etc. to increase the weight.

#### Mass

Bulk; magnitude; body; size.
This army of such mass and charge.

#### Weight

(transitive) To load, burden or oppress someone.

#### Mass

The principal part; the main body.
Night closed upon the pursuit, and aided the mass of the fugitives in their escape.

#### Weight

To assign weights to individual statistics.

#### Mass

The quantity of matter which a body contains, irrespective of its bulk or volume.

#### Weight

(transitive) To bias something; to slant.

#### Mass

To celebrate Mass.

#### Weight

To handicap a horse with a specified weight.

#### Mass

To form or collect into a mass; to form into a collective body; to bring together into masses; to assemble.
But mass them together and they are terrible indeed.

#### Weight

To give a certain amount of force to a throw, kick, hit, etc.

#### Mass

The property of a body that causes it to have weight in a gravitational field

#### Weight

The quality of being heavy; that property of bodies by which they tend toward the center of the earth; the effect of gravitative force, especially when expressed in certain units or standards, as pounds, grams, etc.

#### Mass

(often followed by `of') a large number or amount or extent;
A batch of letters
A deal of trouble
A lot of money
He made a mint on the stock market
It must have cost plenty

#### Weight

The quantity of heaviness; comparative tendency to the center of the earth; the quantity of matter as estimated by the balance, or expressed numerically with reference to some standard unit; as, a mass of stone having the weight of five hundred pounds.
For sorrow, like a heavy-hanging bell,Once set on ringing, with his own weight goes.

#### Mass

An ill-structured collection of similar things (objects or people)

#### Weight

Hence, pressure; burden; as, the weight of care or business.
For the public all this weight he bears.
[He] who singly bore the world's sad weight.

#### Mass

(Roman Catholic Church and Protestant Churches) the celebration of the Eucharist

#### Weight

Importance; power; influence; efficacy; consequence; moment; impressiveness; as, a consideration of vast weight.
In such a point of weight, so near mine honor.

#### Mass

A body of matter without definite shape;
A huge ice mass

#### Weight

A scale, or graduated standard, of heaviness; a mode of estimating weight; as, avoirdupois weight; troy weight; apothecaries' weight.

#### Mass

The common people generally;
Separate the warriors from the mass
Power to the people

#### Weight

A ponderous mass; something heavy; as, a clock weight; a paper weight.
A man leapeth better with weights in his hands.

#### Mass

The property of something that is great in magnitude;
It is cheaper to buy it in bulk
He received a mass of correspondence
The volume of exports

#### Weight

A definite mass of iron, lead, brass, or other metal, to be used for ascertaining the weight of other bodies; as, an ounce weight.

#### Mass

A musical setting for a Mass;
They played a Mass composed by Beethoven

#### Weight

The resistance against which a machine acts, as opposed to the power which moves it.

#### Mass

A sequence of prayers constituting the Christian eucharistic rite;
The priest said Mass

#### Weight

To load with a weight or weights; to load down; to make heavy; to attach weights to; as, to weight a horse or a jockey at a race; to weight a whip handle.
The arrows of satire, . . . weighted with sense.

#### Mass

Join together into a mass or collect or form a mass;
Crowds were massing outside the palace

#### Weight

To assign a weight to; to express by a number the probable accuracy of, as an observation. See Weight of observations, under Weight.

#### Mass

Occurring widely (as to many people);
Mass destruction

#### Weight

To load (fabrics) as with barite, to increase the weight, etc.

#### Mass

Gathered or tending to gather into a mass or whole;
Aggregate expenses include expenses of all divisions combined for the entire year
The aggregated amount of indebtedness

#### Weight

To assign a numerical value expressing relative importance to (a measurement), to be multiplied by the value of the measurement in determining averages or other aggregate quantities; as, they weighted part one of the test twice as heavily as part 2.

#### Mass

A property that determines the object's resistance to acceleration.
Despite its size, the lead ball's mass gives it substantial inertia.

#### Weight

The vertical force exerted by a mass as a result of gravity

#### Mass

The quantity of matter conserved in physical reactions.
The mass of the reactants equals the mass of the products in a closed system.

#### Weight

Sports equipment used in calisthenic exercises and weightlifting; a weight that is not attached to anything and is raised and lowered by use of the hands and arms

#### Weight

The relative importance granted to something;
His opinion carries great weight

#### Weight

An artifact that is heavy

#### Weight

An oppressive feeling of heavy force;
Bowed down by the weight of responsibility

#### Weight

A system of units used to express the weight of something

#### Weight

A unit used to measure weight;
He placed two weights in the scale pan

#### Weight

(statistics) a coefficient assigned to elements of a frequency distribution in order to represent their relative importance

#### Weight

Weight down with a load

#### Weight

Present with a bias;
He biased his presentation so as to please the share holders

#### Weight

Affects the energy required for movement.
Increasing cargo weight means the elevator uses more energy to ascend.

## Common Curiosities

#### Can weight change without a change in mass?

Yes, weight can change if the strength of the gravitational field changes.

#### What units are used to measure mass?

Mass is measured in kilograms or grams.

#### Does mass change with location?

No, an object's mass remains constant regardless of its location.

#### Can we weigh something without gravity?

Without gravity, we cannot measure weight in the conventional sense, but we can still measure mass.

#### Are mass and weight proportional?

Yes, they are proportional; as mass increases, so does weight, and vice versa.

#### Is mass the same as weight?

No, mass is a measure of matter, while weight is the force of gravity on that mass.

#### What units are used to measure weight?

Weight is commonly measured in newtons or pounds.

#### Why do astronauts float in space?

Astronauts float in space because there is no significant gravitational force exerting a weight on them.

#### How do scales measure weight?

Scales measure weight by the amount of force exerted on them, which is due to gravity's pull on the mass.

#### How do we calculate weight from mass?

Weight is calculated by multiplying mass with the acceleration due to gravity (W = m * g).

#### Is weight a scalar or vector quantity?

Weight is a vector quantity because it has both magnitude and direction.

#### Can the mass of an object be zero?

No, every object with matter has a mass; mass cannot be zero if the object exists.

#### Is mass a vector quantity?

No, mass is a scalar quantity; it does not have direction.

#### Does my weight on Earth reflect my true mass?

Your weight on Earth includes your mass and the effect of Earth's gravity.

#### What happens to weight at the center of the Earth?

At the Earth's center, weight would theoretically be zero, as gravity pulls equally in all directions.

## Share Your Discovery

Share via Social Media
Embed This Content
Embed Code
Share Directly via Messenger