How to calculate weight if given the mass

The Formula : Weight (w) = mass(m) * acceleration due to gravity(g).

w = m * g .

g = 9.8 m/s^2

Acceleration (the rate of change of velocity) is caused by a net force on an object. On Earth, one force we can always count on is the ever present force of gravity pulling down on any object that has mass. If gravity is the only force acting on an object, then we find the object will accelerate at a rate of 9.8m/s2 down toward the centre of the Earth (this is often rounded to 10m/s2).