## Blog

## Safety Focus of the Week: Material Weights (Revisited)

Knowing the weight of an object is useful when lifting materials, loading a truck, and measuring drill fluids.

To calculate the weight of an object, you need to know the volume (or dimensions of the volume) and the unit weight. The dimensions allow you to compute a volume. Volume multiplied by the unit weight gives the weight. Notice how the units balance out:

Length = feet

Height = feet

Width = feet

Volume = L x H x W = cubic feet (cf)

Unit Weight = lb/cf

V x UW = lb

For example, a 2-ft x 2-ft by 4-ft concrete block; which has a unit weight of 150 lb/cf:

V = 2 x 2 x 4 = 16 cf

W = 16 cf x 150lb/cf = 2,400 lb

Knowing the block of concrete weighs 2,400 lb, you can select the proper lifting equipment and rigging.

Some common Unit Weights:

Concrete = 150 lb/cf

Steel = 495 lb/cf

Solid Rock = 175 lb/cf

Earth = 125 lb/cf

Wood = 50 lb/cf

This document contains a quick guide to material weights and calculating volumes and areas of different shapes: