For an object at the Earth’s surface, multiply the mass (in pounds) by the “standard gravitational force” of 32.174049 (usually rounded to 32.174), to determine lbf (pound-force). A different ratio must be used if the object is not situated at the surface of the Earth.
Calculate the mass.
Assuming the object is one that is at the surface of the Earth, calculate its mass in pounds.
Add the gravitational force.
Calculate the mass by multiplying it by the “standard gravitational force,” which is 32.174 if the object is on the surface of the Earth.
Determine the lbf.
The result of multiplying Steps 1 and 2 is the lbf, or “pound-force,” which is expressed in foot-pounds per second squared.
A “pound-mass” is a unit of mass, often known as a lbm. “Pound-force” is a unit of measurement for force. Although a pound is commonly used to refer to a unit of mass, the weight of an object varies based on the strength of gravity in a particular location.
Because of the decreased gravity on the moon, a rock that weighs a pound on Earth’s surface weighs less there. The rock’s bulk would stay the same, though.