which can be abbreviated either lb or lbf, to indicate they are pounds of force, not mass. In English units, the unit of mass is the Slug. Force = mass x acceleration so a mass of 1 slug in earths gravitational acceleration (32 ft/sec^2) exerts a force (or weight) of 32 pounds.

In metric units, a mass of 1 kg in earth's gravitational field (9.8 m/s^2) results in a weight of 9.8 N.

1 Pound (lbf) = 4.448 N.

I hate to be picky picky, but when working in English units, its really easy to get turned around if you forget that mass and weight are not the same thing.

Its confusing, because we tend to think of something that weighs a pound force (like a pint of water) as massing a pound, which is not strictly true (it masses 1/32 slug). So we have terms for pound-force (lbf) and pound mass (lbm), which can be very confusing. In metric, a liter of water (about a quart) masses a kilogram, but it weighs 9.8 Newtons.