Freight Class for Corrugated Boxes
Empty corrugated boxes are very light for their volume, so they ship at a high freight class — typically 100 to 250 depending on how tightly they're bundled.
What is the freight class for corrugated boxes?
Flattened, banded bundles of corrugated ship far denser (and at a lower class) than loose or erected boxes. Because the product is almost all air once erected, knockdown-flat shipping is the single biggest lever on the class.
Because freight class is density-driven, there isn’t a single fixed number for corrugated boxes — class 100–250 is the common range. Run your actual dimensions and weight below to pin it down.
Shipping the packaging itself
Corrugated is the strange case where the freight *is* packaging — so its density is purely a function of its own state. Knocked down flat and banded into bundles, corrugated is sheets of board stacked face to face: reasonably dense, easy to pallet, easy to rate. Erected, the identical boxes become their end-use shape — containers of air — and their measured density collapses by an order of magnitude. No other commodity's class swings this hard on a handling decision that costs nothing.
Board weight matters too, in the quieter second order. Heavy double-wall and triple-wall board runs meaningfully more pounds per sheet than single-wall E-flute, so a pallet of KD industrial boxes can measure two classes denser than the same cube of KD retail mailers. When you quote mixed board grades as one shipment, the blended density is what counts — weigh the real pallet rather than extrapolating from last month's different mix.
Corrugated Boxes freight class: worked examples
Density is weight ÷ volume (cubic feet = L × W × H in inches ÷ 1,728). Here is how typical corrugated boxes shipments measure out:
Palletized KD bundles, tightly banded — class 110
Flattened box bundles stacked 45" high on a 48" × 40" pallet, 420 lb.
48 × 40 × 45 = 86,400 in³ ÷ 1,728 = 50.0 ft³. Density = 420 lb ÷ 50.0 ft³.
8.4 lb/ft³ → class 110 — the well-shipped end of the corrugated range.
A single strapped bundle of 25 KD boxes — class 150
One banded bundle of flattened medium shippers, 30" × 24" × 12", 30 lb.
30 × 24 × 12 = 8,640 in³ ÷ 1,728 = 5.0 ft³. Density = 30 lb ÷ 5.0 ft³.
6.0 lb/ft³ → class 150. Loose single bundles rate worse than a consolidated pallet.
The same boxes shipped erected — class 400
Erected empty boxes filling a 48" × 40" × 48" gaylord, 90 lb.
48 × 40 × 48 = 92,160 in³ ÷ 1,728 = 53.3 ft³. Density = 90 lb ÷ 53.3 ft³ = 1.7 lb/ft³.
1.7 lb/ft³ → class 400 — far outside the typical range. Erected boxes are shipped air; keep them flat.
Bundle, band, and stack to the pallet's edge
The KD pallet is won or lost in the strapping. Tight bundles with aligned edges stack into a solid block; loose bundles pillow in the middle, round the stack's shoulders, and add measured inches that are pure air. Band bundles to consistent counts, stack them column-aligned to the pallet's footprint, and cap the top layer flat — a corrugated pallet built this way measures what the board actually is.
And never ship erected boxes if there is any alternative. Erected corrugated rates at the light-freight extremes — class 300–400 territory — which can price the *empty boxes* above the freight cost of the goods they'll eventually carry. If a customer needs boxes pre-erected (some packing lines do), price that shipment knowingly, or quote the KD equivalent plus on-site erecting as the comparison.
What affects corrugated boxes freight class
- Flattened (knock-down) vs. erected
- Bundle banding and stacking
- Pallet vs. loose
- Board grade and thickness
Common corrugated boxes shipments include flattened shipping cartons, bundled mailer boxes, stock corrugated sheets, custom printed boxes.
Class guides covering the 100–250 range:
Calculate the freight class for your corrugated boxes
Enter dimensions and weight to get the density-based class for your exact shipment.
Density-based estimate. Some commodities carry a fixed NMFC class — check our freight class by commodity pages.
Estimated Freight Class
Density
9.75
lb/ft³
Volume
53.33
ft³
Weight
520
lb
9–10.5 lb/ft³ → Class 100
Free PDF includes a watermark. Pro removes it & adds your brand.
Estimates only — verify freight class/NMFC and chargeable weight with your carrier.
How freight class is calculated (density scale)
Freight class is set by density = weight (lb) ÷ volume (ft³). Higher density → lower class → typically lower cost. Volume here is L × W × H × quantity.
| Density (lb/ft³) | Class |
|---|---|
| 50+ | 50 |
| 35 – 50 | 55 |
| 30 – 35 | 60 |
| 22.5 – 30 | 65 |
| 15 – 22.5 | 70 |
| 13.5 – 15 | 77.5 |
| 12 – 13.5 | 85 |
| 10.5 – 12 | 92.5 |
| 9 – 10.5 | 100 |
| 8 – 9 | 110 |
| 7 – 8 | 125 |
| 6 – 7 | 150 |
| 5 – 6 | 175 |
| 4 – 5 | 200 |
| 3 – 4 | 250 |
| 2 – 3 | 300 |
| 1 – 2 | 400 |
| 0 – 1 | 500 |
Frequently asked questions
What freight class is corrugated boxes?
Corrugated Boxes typically ships at freight class 100–250. The exact class is set by density — weight divided by volume — so packaging and dimensions can move it within that range.
What affects the freight class of corrugated boxes?
The main factors are flattened (knock-down) vs. erected, bundle banding and stacking, pallet vs. loose, board grade and thickness. Denser, tightly packed loads rate a lower class and cost less to ship.
How do I find the exact freight class for corrugated boxes?
Measure your shipment and divide weight by volume to get density, then match it to the NMFC scale — the calculator above does this. Confirm the final class and NMFC item number with your carrier before booking.
What freight class are empty boxes?
Flattened and banded, empty corrugated typically measures 6–9 lb/ft³ → class 110–150, and tight palletized bundles do better still. Erected empty boxes measure 1–2 lb/ft³ → class 300–400. Flat versus erected is the entire game.
Does board grade change corrugated freight class?
Yes — double- and triple-wall board weighs substantially more per sheet than single-wall, so KD bundles of heavy board measure denser and can rate a class or two lower on the same cube. Weigh the actual mixed pallet when grades vary.
How should I palletize flattened boxes for the best class?
Consistent banded bundle counts, edges aligned, columns stacked flush to the 48" × 40" footprint, flat top layer, tight strapping. The goal is a solid rectangular block — every pillowed bundle or rounded shoulder adds measured air.