Convert pound-mass to pound-force or solve for mass or acceleration using gravity in ft/s², m/s², or g, with lbf, newton, lbm, and kilogram results.

Required: enter mass and select gravity or custom acceleration.

Known values

Pound Mass to Pound Force Formula

The following equation is used to calculate the Pound-Mass to Pound-Force.

lbf = m × g
  • Where lbf is the pounds of force (lb-f)
  • m is the mass of the object (lbs)
  • g is the acceleration due to gravity (32.174049 ft/s^2)

To calculate the pound-force from pound mass, multiply the mass in pounds by the acceleration in feet per second squared.

Pound Mass to Pound Force Conversion Table (Standard gravity, g₀ = 32.174 ft/s²)
Pound Mass (lbm) Pound Force (lbf)
1/162.011
⅛4.022
1/65.362
¼8.044
⅓10.725
⅜12.065
½16.087
⅝20.109
⅔21.449
¾24.131
⅞28.152
132.174
1¼40.218
1⅓42.899
1½48.261
1¾56.305
264.348
2½80.435
396.522
4128.696
* Rounded to 3 decimals. Assumes standard gravity g₀ = 32.174 ft/s². At 1 g: 1 lbm ≈ 32.174 lbf. (For reference: 1 lbf = 4.44822 N.)

What is the difference between Pound Mass and Pound Force?

A pound-mass is defined as a mass equal to .45359237 kilograms.

A pound-force is the amount of force exerted on one pound mass due to gravity.

How to Calculate Pound Force from Pound Mass?

Example Problem:

The following example outlines the steps and information needed to calculate pound force from pound mass.

First, determine the total mass in pounds. Using an accurate scale, the mass of this object is found to be 15 lbs.

Next, the final and last step is to use the formula above to calculate the pound-force due to gravity.

lbf = lb * g

lbf = 15 * 32.174049

lbf = 482.61 lb-f