How do I calculate dimensional weight?

How do I calculate dimensional weight of a package?

Dimensional-weight pricing is applicable on a per-package basis to all shipments in customer packaging. FedEx packaging may also be subject to dimensional-weight pricing. Dimensional weight is calculated by multiplying length by width by height of your package (round each measurement to the next-higher centimeter) and dividing by 5,000 (standard density in cubic centimeters per kg). Alternatively, if the dimensions are in inches (round each measurement to the next-higher inch), the divisible is 305 (standard density in cubic inches per kg) or 139 (standard density in cubic inches per pound).

Dimensional weight (kg) =	Length x Width x Height (centimeters or inches) ^{_____________________________________________________________}
Dimensional weight (kg) =	5000 for centimeters or 305 for inches

	Dimensional weight (pound) =	Length x Width x Height (inches) ^{__________________________________________}
139 for inches	Dimensional weight (pound) =