“Mass” is a measure of how much matter an object has. “Weight” is a measure of the amount of force brought to bear on an object by gravitational attraction. Gravitational force changes based on location. For example, the gravitational force on the Moon is 0.165 of that here on Earth. Weight changes based on location in direct correlation to the measure of gravitational force at the location. Mass does not change with location. To find an object’s mass using its weight, the formula is Mass equals Weight divided by the Acceleration of Gravity (M = W/G).

Convert the weight measured in pounds to the equivalent in Newtons. In the formula for determining mass based on weight, mass is measured in Newtons. Weight is measured in Kilograms, and the acceleration of gravity on Earth is measured as 9.8 meters per second squared. These are metric system unit measurements. To find the equivalent in U.S. units, you perform conversions. One pound is equal to 4.44822162 Newtons. Therefore, to convert pounds to Newtons, multiply the weight in pounds by 4.44822162. For example, to convert 150 lbs to Newtons, calculate as follows: 150 x 4.44822162 = 667 Newtons.

Divide the weight in Newtons by the acceleration of gravity to determine the mass of an object measured in Kilograms. On Earth, gravity accelerates at 9.8 meters per second squared (9.8 m/s2). For example, to determine the mass of an object weighing 667 Newtons, calculate as follows: 667 Newtons / 9.8 m/s2 = 68 kilograms.

Convert the mass measured in kilograms to the mass in pounds. One kilogram is equal to 2.20462262 pounds. Therefore, to convert kilograms to pounds, multiply the kilogram value by 2.20462262. For example: 68 kilograms x 2.20462262 = 150 pounds.

#### Tip

The “pound” is a U.S. unit which measures the amount of force required to accelerate one slug (a “slug” is the U.S. measurement of mass) one foot per second. Because weight is a measurement of force, technically pounds measure weight. As you may have noted from the example used in the steps, on the surface of Earth where the acceleration of gravity is 9.8 meters per second squared, weight and mass are equal when measured in pound units. How much an object weighs on Earth in pounds is the same as the object’s mass measured in pounds.