The Cylindrical Formula for LTL
If you ship pipes, drums, rolls of textiles, or industrial cylinders, you cannot use the standard Length x Width x Height formula for density. The National Motor Freight Classification (NMFC) mandates a specific "squared" formula for cylindrical objects. Why? Because cylinders take up square space in a trailer—you cannot stack items effectively in the gaps created by a curved edge. Shippers who don't understand this often find their freight re-classified at a much higher, more expensive rate.
The Master Formula
The NMFC volume for a cylinder is calculated as: (Diameter² × Length) / 1728. Note that you use the Greatest Dimension (Diameter) for both Width and Height calculation.
Common Quote Error
Many shippers accidentally use πr² (area of a circle) to find volume. This is wrong for LTL. Carriers charge for the "cube" that the cylinder occupies, not the cylinder's actual internal volume.
Cylindrical Shipping Guidelines
- Greatest Diameter: If your cylinder has a flared end or a protective cap, that maximum point is your official diameter.
- Bundling Rule: For multiple small pipes bundled together, measure the diameter at the widest part of the entire bundle.
- Weight Accuracy: Industrial rolls and pipes are deceptively heavy. Always use a calibrated scale and include the pallet weight.
Calculate Your Cylindrical PCF
Don't trigger an automatic re-bill. Enter your cylinder's Diameter for both Width and Height in the calculator below to get an accurate NMFC result.
Calculate Cylinder PCF ⟶