To convert lbm (pound-mass) to lbf (pound-force) for an object located at the Earth's surface, multiply the mass (in pounds) by the "standard gravitational force" of 32.174049 (typically rounded to 32.174) to calculate lbf. If the object is not located at the Earth's surface, a different ratio must be used.
- Measure the mass
Find the mass of the object in question in pounds, assuming that this is an object at Earth's surface.
- Multiply by gravitational force
If the object is located at the Earth's surface, multiply the mass by the "standard gravitational force" of 32.174.
- Calculate the lbf
After multiplying Step 1 and Step 2, the answer is the lbf, the "pound-force" measured in foot-pound per second-squared.
- Further explanation
An lbm is a unit of mass called a "pound-mass." An lbf is a unit of force called a "pound-force." Colloquially, people speak of a pound as if it is unit of mass, but an object weighs varied amounts in pounds depending on the strength of gravity at a given location. For example, a rock that weighs a pound on Earth's surface weighs less on the moon due to lower gravity. However, the mass of the rock would remain the same.