A freight class number determines a big part of what your LTL shipment actually costs to move, yet most shippers never look at it until a carrier calls asking for more money after pickup. The system was built to give carriers a consistent way to price and handle thousands of different commodities, from steel brackets to patio furniture, without renegotiating every shipment from scratch.
This guide covers what freight class actually is, how the National Motor Freight Classification system assigns it, how to calculate your own class before you book a load, and what happens when the number on your bill of lading doesn’t match what shows up at the dock. For a broader look at how LTL freight moves from pickup to delivery, our LTL shipping guide covers the basics; this one goes deeper into just the classification piece. If you move LTL freight regularly between Ontario, the rest of Canada, or across the border into the US, getting the class right the first time saves money on every shipment.
What Is Freight Class?
Freight class is a standardized rating, running from 50 to 500, that carriers use to price and handle less-than-truckload shipments. It was developed and is maintained by the National Motor Freight Traffic Association (NMFTA), the industry group that publishes the National Motor Freight Classification (NMFC) tariff used across LTL trucking in Canada and the US.
Every commodity that regularly moves LTL, from auto parts to bagged cement to stacked lampshades, has been assigned a class or a range of classes in the NMFC. Classes in the 50 to 100 range generally apply to dense, easy-to-handle freight that ships at a lower rate. Classes from 125 up to 500 apply to freight that is lighter for its size, harder to handle, or carries more risk of damage.
The number matters because it is one of the main inputs a carrier uses to build your rate. Two pallets weighing exactly the same amount can cost very different amounts to ship if one is class 50 metal brackets and the other is class 300 stacked lampshades. Freight class doesn’t apply to full truckload shipments, so if your volume is creeping toward a full trailer, it’s worth comparing LTL and FTL pricing directly rather than assuming LTL is automatically cheaper.
The Four Factors That Determine Freight Class
The NMFC scores every commodity against four characteristics. Density carries the most weight in the final number, but the other three factors can push a class higher even when density alone points to something lower.
Density
Density is the shipment’s weight divided by the trailer space it occupies, expressed in pounds per cubic foot. It drives most of the outcome because it tells a carrier how efficiently a shipment fills their equipment. A pallet of steel brackets that packs 30 pounds into a cubic foot ships far more cheaply than a pallet of foam coolers weighing two pounds in that same cubic foot, because the carrier is hauling more freight per mile of trailer space in the first case.
Stowability
Stowability describes how well a shipment stacks or fits next to other freight in a trailer. Odd shapes, protruding parts, hazardous materials, and anything that can’t be stacked or must ride alone all push the class up, because they waste usable trailer space that could otherwise carry paying freight.
Handling
Handling accounts for the extra labor or equipment a shipment needs to load and unload safely. Freight requiring a liftgate, extra strapping, or hand-carrying because it can’t go on a standard pallet jack usually lands in a higher class than something a forklift operator can load in under a minute.
Liability
Liability reflects the risk of damage, theft, or spoilage a shipment carries for the carrier. High-value electronics, temperature-sensitive freight, and fragile goods carry more exposure, which shows up as a higher class even when density and stowability look reasonable on paper.
How to Calculate Freight Class: Step by Step
Density drives most freight class outcomes for standard commercial shipments, so start there before layering in the other three factors.
Step 1: Measure the Shipment
Measure length, width, and height in inches, including packaging, dunnage, or crating. Measure to the outermost point of the shipment, including anything that overhangs the edge of the pallet.
Step 2: Calculate Cubic Feet
Multiply length by width by height to get cubic inches, then divide by 1,728, the number of cubic inches in a cubic foot.
Example: a pallet measuring 48 x 40 x 50 inches comes to 96,000 cubic inches, or 55.6 cubic feet after dividing by 1,728.
Step 3: Calculate Density
Divide total weight in pounds by the cubic feet figure from Step 2 to get pounds per cubic foot.
Example: that same 55.6 cubic foot pallet weighing 500 pounds works out to roughly 9 pounds per cubic foot.
Step 4: Match Density to a Class
Use the reference table below as a starting point.
| Density (lbs per cubic foot) | Approximate Freight Class |
|---|---|
| 50 or more | Class 50 |
| 35 to 50 | Class 55 |
| 30 to 35 | Class 60 |
| 22.5 to 30 | Class 65 |
| 15 to 22.5 | Class 70 |
| 12 to 15 | Class 85 |
| 10 to 12 | Class 92.5 |
| 8 to 10 | Class 100 |
| 6 to 8 | Class 125 |
| 4 to 6 | Class 175 |
| 2 to 4 | Class 250 |
| 1 to 2 | Class 300 |
| Less than 1 | Class 400 |
Step 5: Adjust for Stowability, Handling, and Liability
If the shipment has an unusual shape, needs special handling, or carries elevated liability risk, the class from the density table may need to move up. When you’re not sure, call your carrier or broker and describe the shipment in detail before it ships. Confirming the class up front costs nothing. A reclassification after pickup usually does.
Freight Class vs. NMFC Code: What’s the Difference
Freight class and NMFC code get used interchangeably in casual conversation, but they answer different questions. The NMFC code, also called an NMFC item number, identifies what the commodity actually is, similar to how a product code identifies a specific item at a retailer. Freight class is the pricing and handling category assigned to that code.
| Freight Class | NMFC Code | |
|---|---|---|
| Answers | How is this priced and handled? | What exactly is this commodity? |
| Format | Number from 50 to 500 | Multi-digit item number, sometimes with a sub-code |
| Set by | Density, stowability, handling, liability | Commodity description in the NMFC tariff |
| Can it change | Yes, if density-based and packaging changes | No, the code identifies the same commodity type |
| Found on | Bill of lading, freight invoice | NMFC tariff, carrier classification lookup |
Some commodities carry a single fixed class regardless of the shipment. Others are listed in the NMFC as density-based items, meaning the class shifts depending on the measured density of that specific shipment. Anything density-based is exactly why the calculation above matters. Guess wrong on a density-based item and the carrier will correct it for you, usually at your expense.
Freight Class Reference Chart: Class 50 Through Class 500
The table below gives a general sense of where common commodity types land. Treat it as a starting reference, not a substitute for confirming the exact NMFC item number for your specific product.
| Class | Typical Density | Example Commodities |
|---|---|---|
| 50 | 50+ lbs/cu ft | Steel parts, machinery, bricks |
| 55 | 35 to 50 lbs/cu ft | Bottled beverages, hardwood flooring |
| 60 | 30 to 35 lbs/cu ft | Car parts, ceramic tile |
| 65 | 22.5 to 30 lbs/cu ft | Auto accessories, bagged cement |
| 70 | 15 to 22.5 lbs/cu ft | Canned goods, car parts |
| 77.5 | 13.5 to 15 lbs/cu ft | Tires, plumbing fixtures |
| 85 | 12 to 13.5 lbs/cu ft | Crated machinery, pharmaceuticals |
| 92.5 | 10 to 12 lbs/cu ft | Computer monitors, refrigerators |
| 100 | 8 to 10 lbs/cu ft | Boxed electronics, wine cases |
| 110 | 7 to 8 lbs/cu ft | Bookcases, framed artwork |
| 125 | 6 to 7 lbs/cu ft | Small household appliances |
| 150 | 5 to 6 lbs/cu ft | Cabinets, auto sheet metal parts |
| 175 | 4 to 5 lbs/cu ft | Clothing, stuffed furniture |
| 200 | 3 to 4 lbs/cu ft | Sheet metal parts, aluminum tables |
| 250 | 2 to 3 lbs/cu ft | Bamboo furniture, mattresses |
| 300 | 1 to 2 lbs/cu ft | Wood cabinets, model boats |
| 400 | 0.5 to 1 lbs/cu ft | Unassembled wood furniture, deer antlers |
| 500 | Less than 0.5 lbs/cu ft | Bags of gold dust, ping-pong balls |
What Happens When Your Freight Class Is Wrong
Carriers inspect and reweigh LTL freight at their terminals as a matter of routine, and a mismatch between the class on your bill of lading and what actually shows up on their dock triggers a reclassification. The carrier adjusts the class to match what they measured, rebills the shipment at the correct rate, and in most cases adds an inspection or reclassification fee on top.
These corrections rarely go in the shipper’s favor. A shipment listed at class 70 that measures out to class 100 gets rebilled at the higher rate plus a fee, and the freight is often already in transit or delivered by the time the invoice shows up. Repeated misclassification on the same account can also flag future shipments for closer inspection, which slows down freight that would otherwise move without a hitch.
| Mistake | Consequence | Fix |
|---|---|---|
| Estimating weight instead of weighing | Reclassification and rebilling once the carrier weighs it | Use a certified scale before every shipment |
| Reusing an old class number | Class no longer matches actual density if packaging changed | Recalculate density for every shipment |
| Ignoring pallet overhang in measurements | Understated cubic feet, and a class correction later | Measure to the outermost point, including overhang |
| Not disclosing special handling needs | Carrier applies a handling surcharge on top of a reclassification | Disclose special handling requirements at booking |
| Mixing commodities on one pallet without noting it | Carrier assigns the highest applicable class to the whole pallet | Separate commodities or clearly declare the mixed load |
Freight Class on Cross-Border Canada-U.S. LTL Shipments
Freight class applies the same way on cross-border LTL shipments as it does domestically, but a wrong class causes more damage when it’s tangled up with customs paperwork too. A reclassification at a US terminal can hold a shipment moving from Canada to the US, or one coming from the US into Canada, while the paperwork gets sorted out on both sides of the line.
The Canada Border Services Agency requires accurate commercial documentation before goods can clear into Canada, and the freight class and description on your bill of lading need to match the commercial invoice a customs broker files on your behalf. A mismatch between what’s declared and what the carrier finds at the dock adds a second layer of delay on top of a standard reclassification.
| Document | Purpose |
|---|---|
| Bill of lading with accurate freight class and description | Matches the physical shipment to what’s declared for pricing and customs |
| Commercial invoice | Establishes value and origin for CBSA and U.S. Customs and Border Protection |
| Proof of origin (where required) | Supports duty and tariff treatment under applicable trade agreements |
| NMFC item number, if known | Speeds up carrier verification and reduces reclassification risk |
| Customs broker contact information | Ensures release paperwork is filed correctly on both sides of the border |
Practical Tips for Getting Your Freight Class Right the First Time
- Weigh and measure every shipment instead of reusing numbers from a similar load months ago. Packaging changes, product specs change, and so does density.
- Keep a record of your NMFC item numbers for products you ship regularly, so your team isn’t guessing at class on every booking.
- Photograph unusual freight before it ships. A photo showing an odd shape or protruding part helps if a carrier disputes the stowability factor later.
- Ask your carrier or broker directly when a shipment doesn’t fit neatly into a category you’ve used before. A short phone call is cheaper than a reclassification fee.
- Review freight class on recurring lanes once or twice a year, especially if your packaging or supplier has changed.
Freight Class and Your LTL Rate: Why the Number on the BOL Matters
Freight class feeds directly into what an LTL shipment actually costs, alongside distance, accessorial charges, and current market capacity. Two shippers moving the same weight on the same lane can pay noticeably different rates purely because one has a lower freight class than the other. If you’re focused on getting the best LTL rate, an accurate, well-documented freight class is one of the few variables you actually control, unlike fuel prices or seasonal capacity swings.
This is also where packaging decisions pay off. Palletizing loose boxes, consolidating a shipment into fewer, denser units, or switching an oversized flatbed load into a standard dry van pallet can shift a shipment into a lower class and a lower rate, without changing what’s actually inside the box.
When a Calculator Isn’t Enough: Working With Your Carrier or Broker
Online freight class calculators are useful for a quick estimate, and the formula behind them is exactly what’s laid out in the steps above. Where they fall short is on anything that doesn’t fit a standard box shape, anything with mixed commodities on one pallet, or freight sitting close to a class boundary where a small measurement error changes the number.
For trade show freight, irregularly shaped equipment, or anything requiring limited access delivery, a calculator gets you in the right neighborhood, but a conversation with your carrier or broker before the shipment leaves the dock is what actually prevents a reclassification. Getting it wrong on freight already staged for pickup, or freight that’s been through warehouse storage and repackaged, is far more expensive than a short phone call beforehand. It also matters for time-sensitive loads. A shipment held up for reclassification when it needed expedited handling turns a rush order into exactly the kind of delay that drives up the real cost of late freight for manufacturers and distributors.
RoadLINX handles LTL shipping across Canada and cross-border into the US, and our team will walk through freight class with you before a shipment books, not after a reclassification invoice shows up. If you’re not sure how a specific shipment will classify, request a freight quote and we’ll confirm it with you directly.
Frequently Asked Questions
What is freight class?
Freight class is a standardized rating from 50 to 500 used to price and handle LTL shipments. It’s based on density, stowability, handling, and liability, and it comes from the National Motor Freight Classification tariff used across LTL trucking in Canada and the US.
Who created the freight class system?
The National Motor Freight Traffic Association (NMFTA), a US-based trade association, developed and maintains the National Motor Freight Classification. Most LTL carriers operating in Canada and the US reference this same classification system for pricing and handling.
What is NMFC?
NMFC stands for National Motor Freight Classification, the tariff that lists thousands of commodities along with their assigned freight class or class range. Every commodity in the NMFC has a corresponding item number that carriers use to identify exactly what’s being shipped.
How do I calculate my freight class?
Measure length, width, and height in inches, multiply them together, and divide by 1,728 to get cubic feet. Divide the shipment’s weight by that cubic feet figure to get density in pounds per cubic foot, then match that number to a class using a density reference chart.
What is freight density and why does it matter?
Freight density is weight divided by the space a shipment takes up in a trailer, measured in pounds per cubic foot. It’s the single biggest factor in freight class because it tells a carrier how efficiently a shipment uses their equipment.
What is freight class 70?
Freight class 70 typically applies to moderately dense, stackable freight such as canned goods, auto parts, or car accessories. It sits roughly in the middle of the classification scale and ships at a moderate rate compared to very dense or very light freight.
What is freight class 50?
Freight class 50 is the lowest and least expensive standard class, reserved for very dense, durable freight like steel parts, bricks, or hardware. Dense, easy-to-handle freight uses trailer space efficiently, which keeps the shipping rate low.
What is freight class 100?
Freight class 100 generally covers moderate-density freight such as boxed electronics or wine cases. It reflects a balance between how much space the freight occupies and how much care it needs during handling.
What happens if I use the wrong freight class?
A carrier that finds a mismatch during inspection will reclassify the shipment to the correct class, rebill it at the corrected rate, and typically add an inspection or reclassification fee. This usually happens after the freight is already in transit or delivered.
What is a reclassification fee?
A reclassification fee is a charge a carrier applies when the freight class or weight declared on the bill of lading doesn’t match what they measure at their terminal. It covers the cost of correcting the shipment record and rebilling at the accurate rate.
Does freight class affect full truckload shipments?
No. Freight class is specific to LTL pricing. Full truckload shipments are priced by the trailer, not by individual commodity classification, so a freight class number generally isn’t required for a dedicated truckload move.
Can two shippers have different classes for the same product?
Yes, if the packaging or density differs between shipments. A product classified as density-based in the NMFC can carry a different class depending on how it’s packaged, palletized, and measured for that specific shipment.
What is an NMFC item number?
An NMFC item number identifies a specific commodity within the National Motor Freight Classification tariff, similar to how a product code identifies an item at a retailer. It points to the freight class or class range that applies to that commodity.
How do carriers verify freight class?
Carriers reweigh and re-measure shipments at their terminals using dock scales and dimensioning equipment. If the class declared on the bill of lading doesn’t match what they find, they adjust it and rebill the shipment accordingly.
Can I negotiate my freight class?
Freight class itself isn’t negotiable since it’s based on measurable characteristics like density and handling requirements. What you can influence is the actual density and packaging of your shipment, which can shift it into a lower class.
Does packaging affect freight class?
Yes. Consolidating loose items onto a single dense pallet, reducing wasted space, and securing awkward shapes can lower a shipment’s effective class. Poor packaging that increases handling difficulty or damage risk can push the class higher instead.
Is freight class the same in Canada as the US?
Most LTL carriers moving freight in Canada, including cross-border lanes, reference the same NMFC classification system used in the US. Some Canadian domestic carriers use their own tariff structures, so it’s worth confirming with your specific carrier on purely domestic Canadian lanes.
What’s the easiest way to avoid freight class disputes?
Weigh and measure every shipment instead of relying on past numbers, keep records of the NMFC item numbers you use regularly, and call your carrier or broker before shipping anything unusual. A short conversation up front is cheaper than a reclassification after pickup.
