Freight Class for Cardboard Boxes
Cardboard boxes ship best flattened — bundled flat they're denser and lower-class, while loose or assembled boxes rate as high as class 250.
What is the freight class for cardboard boxes?
“Cardboard” and “corrugated” are rated the same way: by density. The trick is always to ship them knocked-down flat and banded into tight bundles. Erected or loosely loaded boxes waste trailer space and rate at a high class, raising your cost.
Because freight class is density-driven, there isn’t a single fixed number for cardboard boxes — class 100–250 is the common range. Run your actual dimensions and weight below to pin it down.
Cardboard ships denser than its reputation
Cardboard has a reputation as miserable freight, and it's half-earned — but only half. Flat cardboard is thin sheets of solid paperboard, and thin flat things bundle into surprisingly dense stacks: a banded brick of mailers or folding cartons can measure over 20 lb/ft³, right down with bottled goods in the cheap classes. The miserable version is cardboard with its shape restored — assembled gift boxes, erected shippers, loose piles — where the freight is again mostly the air the boxes were designed to hold.
The other cardboard-specific variable is the size mix. Moving kits and retail box assortments bundle small, medium and large flats together, and mismatched flat sizes stack like a badly shuffled deck — edges overhanging, voids between bundles. Sorting flats by footprint before banding, or banding assortments so that same-size flats nest within each bundle, keeps an assorted shipment measuring close to what uniform stock would.
Cardboard Boxes freight class: worked examples
Density is weight ÷ volume (cubic feet = L × W × H in inches ÷ 1,728). Here is how typical cardboard boxes shipments measure out:
Banded e-commerce mailers — class 65
A tight brick of 200 flat mailers, 18" × 12" × 14", 42 lb.
18 × 12 × 14 = 3,024 in³ ÷ 1,728 = 1.75 ft³. Density = 42 lb ÷ 1.75 ft³.
24.0 lb/ft³ → class 65 — flat thin board is dense freight.
A bundle of 25 flat moving boxes — class 92.5
One banded bundle of KD medium moving boxes, 24" × 18" × 10", 28 lb.
24 × 18 × 10 = 4,320 in³ ÷ 1,728 = 2.5 ft³. Density = 28 lb ÷ 2.5 ft³.
11.2 lb/ft³ → class 92.5.
Palletized mixed box kits — class 100
Assorted-size flat bundles stacked 48" high on a 48" × 40" pallet, 520 lb.
48 × 40 × 48 = 92,160 in³ ÷ 1,728 = 53.3 ft³. Density = 520 lb ÷ 53.3 ft³.
9.8 lb/ft³ → class 100. Size-sorting the bundles tighter pushes this toward 92.5.
Kits, mailers, and the assortment problem
E-commerce mailers and folding cartons are the best-case cardboard: small, uniform, thin, and dense in high-count bundles. If mailers are part of a mixed shipment, band them as their own bricks and use them the way a dense commodity is always used — as ballast that raises the whole pallet's blended density.
Moving-box kits sold as retail units bring a subtler trap: the kit often includes tape, cushioning and a handle-carton that force a larger, half-empty master pack. Shipping kit master-packs as they land in retail inventory can rate two classes worse than shipping the same boxes re-bundled flat. When volume justifies it, break kits to flats for the linehaul and re-kit at destination — and let the calculator below price the difference for your actual counts.
What affects cardboard boxes freight class
- Knock-down flat vs. assembled
- Tight banding into bundles
- Pallet stacking
- Box size mix
Common cardboard boxes shipments include flat-packed cartons, banded box bundles, folding cartons, gift and retail boxes.
Class guides covering the 100–250 range:
Calculate the freight class for your cardboard 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 cardboard boxes?
Cardboard 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 cardboard boxes?
The main factors are knock-down flat vs. assembled, tight banding into bundles, pallet stacking, box size mix. Denser, tightly packed loads rate a lower class and cost less to ship.
How do I find the exact freight class for cardboard 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 cardboard boxes?
Flat and tightly bundled: commonly 9–12 lb/ft³ → class 92.5–100 palletized, and dense flat stock like mailers measures far better still. Assembled or loose boxes rate at the light-freight extremes. Flat versus assembled decides everything.
What's the cheapest way to ship moving boxes?
Knocked-down flat, banded into same-size bundles, stacked flush on a pallet. Retail kit master-packs with tape and cushioning inside rate worse — for volume moves, ship flats and re-kit at the destination.
Is cardboard classed differently from corrugated board?
No — both are density-rated the same way. Thin folding-carton board actually bundles denser than fluted corrugated, so cardboard flats often measure a class better than corrugated bundles of the same footprint.