Weight

The Weight Calculator (w = m•g) computes net force of gravity on a mass (its weight)  based on the acceleration due to gravity (g) and mass (m).

INSTRUCTIONS: Choose units and enter the following:

• (m) mass
• (g) acceleration due to gravity 

Weight (w): The calculator returns weight (w) in newtons.  However, this can be automatically converted to other force units via the pull-down menu.

The Math / Science

Weight is the force of gravity on a mass. Newton's second law formula (F = m•a) shows the relationship between mass, acceleration and force.  The weight formula uses Newton's second law:

w = m • g

where:

• w is the weight (force of gravity on a mass)
• m is the mass
• g is the acceleration due to gravity.

Acceleration Due to Gravity (g)

The acceleration due to gravity is different based on the mass of the star, planet, moon or asteroid and the distance from its center of mass and its surface.  For that reason, gravity has a lesser pull on bodies of lesser mass or density than the Earth such as the moon.  The formula for acceleration due to gravity is:
    
           g = (G•M)/R²

Where:

• g is the acceleration due to gravity.
• G is the Universal Gravitational Constant (G)
• M is the mass of the object (e.g. planet)
• R is the distance to the center of mass of the object.

Acceleration due to gravity:

• g(Sun) = 274 m/s² 
• g(Mercury) = 3.7 m/s²
• g(Venus) = 8.87 m/s² 
• g(Moon) =  1.62 m/s²
• g(Earth) = 9.80665 m/s² 
• g(Mars) = 3.71 m/s² 
• g(Jupiter) = 24.79 m/s² 
• g(Saturn) = 10.44 m/s² 
• g(Uranus) = 8.87 m/s²
• g(Neptune) = 11.15 m/s² 
• g(Pluto) = 0.62 m/s²

Related Calculators:

• Force of Buoyancy