Load weight estimation is crucial when rigging or planning a lift. The LGH workshop uses the Journeyman Rigger’s Reference Card panel 6 to help provide a solution for weight estimation. You can refer to this reference card below!
Area of a Circle
The area of a circle can be calculated with either (Pi x radius squared) or (dia. x dia. x .80), and both arrive at very similar values for Area of a Circle. For riggers in the field, we use the dia. x dia. x .80 method since it is faster and simpler.
If circumference is desired, a person can use Pi x diameter, officially 3.1416 x d, or for quick figuring in the field, 3.2 x diameter.