Free Freight Class calculator
Enter your shipment's weight and dimensions to get its density in pounds per cubic foot and the NMFC freight class it maps to — with the full density-band ladder so you can see the class above and below — updated live, as you type.
On this page14 sections
Estimates the density-based NMFC class only. Final class can depend on stowability, handling and liability — confirm with your carrier.
Results are estimates. Consult a professional.
How the freight class calculator works
Freight class turns on one number: density. The calculator takes your shipment's weight and its three dimensions, works out the volume in cubic feet, then divides weight by volume to get density in pounds per cubic foot. That density lands in one of eighteen standard bands, and each band maps to a single NMFC freight class from 50 to 500. Denser freight gets a lower class and a lower rate; light, bulky freight gets a higher class and costs more to move.
What the class number tells you
The class is a pricing input, not a description of your goods. Carriers and brokers feed it into their rate tables: the same lane and weight cost more at class 175 than at class 70. Getting the density right means getting the class right, and getting the class right is what keeps the invoice from arriving with a reclassification fee bolted on. The class is the single field on a bill of lading most likely to be re-rated by the carrier.
What goes into your freight class estimate
A density-based class is built from two measurements: weight and volume. Both have to reflect the real, packaged, palletized shipment — not the bare product — or the class comes out wrong.
Weight — the whole shipment
Use the total shipping weight: product, packaging, dunnage and pallet. A 460 lb product on a 40 lb pallet is a 500 lb shipment. Carriers weigh freight on a certified scale at the terminal, so an honest number here is what stops a weight correction later.
Volume — measure the footprint, not the product
Volume is length times width times height in inches, divided by 1728. Measure to the furthest points of the load, including any overhang and the pallet itself. A box that sits proud of the pallet edge, or freight that cannot be stacked, takes up the full cube — and that is the cube the carrier charges for.
Density — where the two meet
Dividing weight by volume gives density, the figure that decides the class. The lever you can sometimes move is volume: tighter packaging or a smaller pallet raises density, which can drop you into a lower class and a cheaper rate. The same product shipped loose versus shrink-wrapped tight can land two classes apart.
A worked example using the freight class calculator
Maria is shipping a palletized machine part. The load sits on a standard 48 × 40 in pallet and stands 48 in tall once wrapped, and the whole thing weighs 500 lb on the warehouse scale. She needs the freight class to get an accurate LTL quote.
Step 1 — Find the volume in cubic feet
Multiply the inches, then divide by 1728: (48 × 40 × 48) ÷ 1728 = 92,160 ÷ 1728 = 53.33 ft³.
Step 2 — Work out the density
Divide weight by volume: 500 ÷ 53.33 = 9.38 lb/ft³.
Step 3 — Map the density to a class
A density of 9.38 lb/ft³ falls in the 9-to-10.5 band, which maps to class 100 — close to the middle of the scale, which is where a lot of general palletized freight lands.
Freight class density chart (lb/ft³ to NMFC class)
This is the full density-to-class ladder. Find your density in the left column and read the class on the right. Bands are lower-bound-inclusive — a density of exactly 35 lb/ft³ is class 55, not 60. Most carrier calculators show you only the one class you land on; the whole table is here so you can see how close you are to the band above or below.
| Density (lb/ft³) | Freight 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 |
Each band runs from its lower number up to (but not including) the next. Density-to-class bands follow the standard NMFC table published by Freightquote and other LTL carriers.
What else affects freight class besides density
Density is the primary driver, and since the 2025 NMFC overhaul most standard commodities are classed on density alone. But the National Motor Freight Classification rates four characteristics, and for some goods the other three can override the density-based class. Know them before you trust a pure density number.
| Factor | What it measures | Effect on class |
|---|---|---|
| Density | Weight per cubic foot (the figure this tool computes) | Primary driver — higher density, lower class |
| Stowability | How easily the freight loads alongside other shipments | Hazardous, oversized or awkward loads can raise the class |
| Handling | How hard it is to load, unload and move through a terminal | Fragile, heavy or odd-shaped items can raise the class |
| Liability | Risk of damage, theft, perishing, or harming nearby freight | High-value or perishable goods can raise the class |
The four classification factors defined by the NMFC. Density is the one you control with measurement; the other three are properties of the commodity.
A density figure gets you a reliable estimate for ordinary palletized goods. For anything hazardous, fragile, high-value or unusually shaped, treat the calculator's class as a starting point and confirm the listed NMFC item with your carrier or broker.
How to get an accurate freight class
Accurate inputs are the whole game. A class that is one band off can mean a reclassification fee that wipes out any saving you thought you had. These steps keep the number honest.
- Weigh the packaged shipment on a real scale — product, packaging and pallet together. Guessed weights are the most common reason carriers re-rate a load.
- Measure to the extreme points — include overhang, bulging boxes and the pallet. Round each dimension up to the next inch; carriers measure the cube they have to load.
- Tighten the packaging if you can — shrink-wrapping a load or using a smaller pallet raises density, which can drop you into a lower class.
- Check the band edges — if your density sits just under a threshold, a small packaging change can cross it. Use the chart above to see the next class up and down.
- Confirm the NMFC item for tricky freight — anything hazardous, fragile or high-value can carry a fixed class regardless of density. Verify it with your carrier before booking.
Once you have the class, you can price the move. Pair it with our fuel cost calculator to estimate the driving leg of an owner-operated haul, or check vehicle efficiency with the gas mileage calculator.
How accurate is this freight class calculator?
The density math is exact. Weight divided by volume, with volume from length times width times height divided by 1728, is the precise density of your shipment, and the band lookup is the published NMFC table. If your measurements are right, the density-based class is right.
The estimate is only as good as the numbers you feed it, and density is not the only factor. For ordinary palletized freight the density class is what the carrier will use. For hazardous, fragile, perishable or high-value goods, stowability, handling and liability can set a different class no matter what the density says. Treat this as a strong estimate for general freight, confirm the exact NMFC item for anything unusual, and always weigh and measure the real packaged load before you book.
Freight class definitions
Sources and references
NMFTA — National Motor Freight Traffic Association, the body that maintains the National Motor Freight Classification (NMFC) standard.Freightquote — Freight Class Calculator & Chart (density-to-class band table).FedEx Freight — Freight Class Calculator (density formula and method).Old Dominion Freight Line — Freight Density Calculator (carrier density tool).Frequently asked questions about the free Freight Class calculator
About this Freight Class calculator
This freight class calculator runs entirely in your browser — nothing you enter is sent anywhere. It works out your shipment's density from its weight and dimensions, then maps that density onto the standard NMFC class bands, so the same inputs always return the same class.
Find it alongside the rest of our transportation calculators, part of the full library of free online calculators. Density sets the class for ordinary palletized freight; stowability, handling and liability can override it for unusual goods, so confirm the NMFC item with your carrier before booking.