wikiHow Object Mass Calculator To calculate the mass of an object, you need to use its weight and the acceleration due to gravity at the location where the object is being measured. The formula to calculate the mass of an object is: mass = weight / acceleration due to gravity where: weight is the force exerted on the object due to gravity. This can be measured using a scale or balance, and is usually measured in Newtons (N) or pounds (lbs). acceleration due to gravity is the acceleration that an object experiences due to the gravitational force of the Earth. It is a constant value of approximately 9.81 meters per second squared (m/s²) at the Earth's surface. To use this formula, simply divide the weight of the object in Newtons or pounds by the acceleration due to gravity in meters per second squared: mass (in kilograms) = weight (in Newtons) / 9.81 mass (in pounds) = weight (in pounds) / 32.174 For example, if an object weighs 100 Newtons, its mass would be: mass = 100 N / 9.81 = 10.19 kg Or, if an object weighs 50 pounds, its mass would be: mass = 50 lbs / 32.174 = 1.56 kg Page