To convert lbm to lbf for an object located at the surface of the Earth, multiply the mass (in pounds) by the “standard gravitational force” of 32.174049 (usually rounded to 32.174). If the object is not on the surface of the Earth, a different ratio must be applied.

## Calculate the mass

Assuming that the object in question is located at the Earth’s surface, determine its mass in pounds.

## Increasing via gravitational force

Multiply the mass by the “standard gravitational force” of 32.174 if the object is located at the Earth’s surface.

## Determine the lbf

After multiplying Steps 1 and 2, the outcome is the lbf, which is measured in foot-pounds per second squared.

## Further clarification

A pound-mass is a unit of mass denoted by the symbol lbm. A pound-force is the unit of force denoted by the symbol lbf. People commonly refer to a pound as a unit of mass, however an object’s weight in pounds varies based on the gravitational pull of its location. Due to decreased gravity, a rock that weighs one pound on Earth’s surface weighs less on the moon. However, the rock’s mass would stay unchanged.