Freight class calculator

Enter your handling units and get density, cube, and freight class — scored against both the long-published 18-step density guideline and the NMFC density sub-provision scale that expanded to 13 subs on April 7, 2026. Multi-pallet shipments welcome. Nothing leaves your browser.

Shipment

Pieces	Length (in)	Width (in)	Height (in)	Weight (lb, line total)

How freight class is calculated

Density does most of the work. Multiply length × width × height for each handling unit to get cubic inches, divide by 1,728 to get cubic feet, then divide total weight by total cubic feet. That number — pounds per cubic foot, or PCF — is what maps to a class.

Measure the shipping dimensions, not the product's. Pallet height includes the pallet. Anything that overhangs counts. A skid measured at 48×40×48 that actually ships at 48×40×52 because of a stretch-wrapped cap is the single most common source of a reclassification bill.

The two density scales, and why they disagree

Most freight class calculators online show one table: the 18-step density guideline that runs from class 50 down to class 500. It is a reasonable predictor and it is what carriers' sales tools have displayed for years.

It is not, however, the scale written into density-based NMFC items. The National Motor Freight Traffic Association's Docket 2025-1 moved roughly 2,000 commodity listings onto density provisions starting July 19, 2025, using an 11-sub structure. That structure was then expanded to 13 subs — adding classes 55 and 50 at the dense end — effective April 7, 2026.

The practical consequence: the two scales do not line up everywhere. A shipment at 40 PCF reads as class 55 on both. A shipment at 14 PCF reads 77.5 on the 18-step guideline but 85 under Sub 8, because the sub-provision runs a single band from 12 to 15 PCF where the guideline splits at 13.5. The same thing happens at 8 to 9 PCF (110 versus 100), 6 to 7 (150 versus 125), and every band below 4. The calculator above scores both and tells you when they diverge, because the one that governs your shipment is the one written into your NMFC item.

Density guideline — 18 steps

Density (lb per cubic foot)	Class
50 or more	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
Under 1	500

NMFC density sub-provisions — 13 subs

Effective April 7, 2026. Subs 11, 12 and 13 are the ones added or amended in the expansion — they are what let genuinely dense freight reach classes 60, 55 and 50.

Sub	Density (lb per cubic foot)	Class
Sub 13	50 or more	50
Sub 12	35 – 50	55
Sub 11	30 – 35	60
Sub 10	22.5 – 30	65
Sub 9	15 – 22.5	70
Sub 8	12 – 15	85
Sub 7	10 – 12	92.5
Sub 6	8 – 10	100
Sub 5	6 – 8	125
Sub 4	4 – 6	175
Sub 3	2 – 4	250
Sub 2	1 – 2	300
Sub 1	Under 1	400

Freight class for multiple pallets

Most freight class calculators online take one box. Real shipments are rarely one box, and a mixed shipment is not rated by averaging the classes of its parts.

Carriers rate a multiple-pallet shipment on its combined density: add up the weight of every handling unit, add up the cube of every handling unit, and divide. Add a line above for each pallet, skid, crate or carton and the calculator does exactly that.

The consequence catches people out. Four dense pallets at 20 PCF plus one light, bulky skid at 3 PCF do not ship as class 65 with an exception — they ship as one shipment whose combined density might land at 9 or 10 PCF, pulling everything into a much higher class. If one item is dragging the whole shipment down, the question worth asking your carrier is whether to tender it separately.

Working the other way: if you have not built the pallets yet, the pallet calculator shows how your cartons stack and what each finished pallet will weigh and measure — which is what you would type in above.

What density does not decide

Density is one of four factors in classification. The others are stowability, handling, and liability. A drum of something corrosive and a drum of sand can share a density and not share a class. Freight that cannot be stacked, cannot be forklifted from two sides, is unusually valuable, or is regulated as hazardous carries provisions that override the density read.

So treat the class above as the density-derived answer — correct arithmetic, and usually the right answer for ordinary palletized goods — then confirm against the NMFC item that actually governs your commodity before you tender the shipment.

Questions people actually ask

Why did my carrier reclassify my shipment?

Almost always because the dimensions or weight on the bill of lading did not match what the carrier's dimensioner measured at the dock. Wrapped pallets grow: a 48-inch stack that ships at 52 inches with a capped top loses about 8 percent of its density, which is enough to cross a class break. Measure the wrapped, loaded unit at its widest and tallest point, including overhang and the pallet itself.

Is a lower freight class always cheaper?

Lower class means denser freight and a lower rate per hundredweight, so for the same weight a lower class costs less. It does not follow that you should push for a lower class. Understating class produces a reclassification, the corrected charge, and often an inspection fee — a worse outcome than quoting it right.

What changed in the NMFC in 2025 and 2026?

Docket 2025-1, effective July 19, 2025, consolidated roughly 2,000 commodity listings and moved many of them onto density-based provisions using an 11-sub scale. That scale was expanded to 13 subs effective April 7, 2026, adding class 55 for densities from 35 to under 50 PCF and class 50 at 50 PCF and above. The NMFTA also added handling, stowability and liability identifiers to many items.

Does this calculator work for multiple pallets?

Yes. Add a line per handling unit. Density for a mixed shipment is total weight divided by total cube across every unit, which is how carriers rate it — not an average of the individual densities. That is why a single light, bulky skid can pull an otherwise dense shipment into a higher class.

Do I still need an NMFC number on the bill of lading?

Carriers generally expect the NMFC item number alongside the class. The class alone describes the rate basis; the item number identifies which provision you claimed. Leaving it off invites the carrier to classify the freight for you.