Mass vs. Weight

Though closely related, mass and weight are slightly different. On Earth, under the force of gravity, mass and weight are the same. However, when the force of gravity changes, weight changes along with it while mass remains the same.

Mass is the amount of matter in an object, measured by its inertia. It causes matter to have weight in a gravitational field. A person's mass on the Moon is the same as their mass on Earth, despite the difference in gravitational pull. Mass is measured in units such as grams, kilograms, ounces, and pounds.

Weight is a measurement of how heavy an object is. It is affected by an object's mass and the force of gravity. A person's weight on the Moon is less than their weight on Earth because of the difference in gravitational pull. Weight is commonly measured in units such as grams, kilograms, ounces, and pounds, but scientifically it is measured in Newtons.