Freight Class Calculator
Estimate your NMFC freight class from dimensions, weight, density, handling and liability. Use this as a planning tool before you book LTL shipments.
Disclaimer: This tool provides an educational estimate only. Official NMFC class and charges are determined by the carrier / NMFTA.
Freight Class & Density Calculator
Results (estimate only)
Use this as a guide. The carrier or NMFTA will determine the official NMFC class.
- Cubic volume
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- Density
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- Base class range (by density)
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- Estimated freight class
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Quick tip
Enter your shipment dimensions and weight to see how density affects your LTL freight class.
Typical density-to-freight-class reference
NMFC freight class is defined by the National Motor Freight Traffic Association (NMFTA). Carriers often use density as a starting point. The table below shows a common, simplified mapping used by many LTL carriers.
| Density (lb/ft³) | Typical class | Notes |
|---|---|---|
| > 50 | 50 | Very dense freight (e.g., metal bars, machinery parts) |
| 35 – 50 | 55 | High density, easy to handle |
| 30 – 35 | 60 | High density palletized freight |
| 22.5 – 30 | 65 | Common industrial freight |
| 15 – 22.5 | 70 – 85 | Moderate density |
| 10 – 15 | 85 – 100 | Typical consumer goods on pallets |
| 8 – 10 | 100 – 125 | Bulkier items, lower density |
| 6 – 8 | 125 – 150 | Light but not extremely bulky |
| 4 – 6 | 150 – 250 | Bulky, low-density freight |
| < 4 | 250 – 500 | Very light / bulky items (e.g., foam, assembled furniture) |
Exact class depends on the specific NMFC item description, packaging, stowability, and liability. Carriers may use slightly different density breaks.
What is freight class?
Freight class is a standardized way to categorize less-than-truckload (LTL) shipments in the United States. The National Motor Freight Traffic Association (NMFTA) assigns each commodity an NMFC item number and a corresponding freight class from 50 (very dense, lower cost) to 500 (very light, higher cost).
Carriers and 3PLs use freight class to determine pricing, liability limits, and how freight is loaded. Getting the class right helps you avoid reclass fees, rebills, and shipment delays.
The four main freight class factors
- Density – How heavy the freight is relative to the space it occupies (lb/ft³). Higher density usually means a lower class.
- Handling – How easy it is to move the freight with standard equipment. Long, fragile, or unstable loads may require a higher class.
- Stowability – How well the freight fits with other freight in a trailer. Odd shapes, hazardous materials, or restrictions can increase class.
- Liability – The value of the freight and its susceptibility to damage or theft. High-value or easily damaged goods may be assigned a higher class.
How this freight class calculator works
This tool focuses on the most quantifiable factor: density. It then applies small adjustments for handling and liability to give you a more realistic estimate than a simple density-only calculator.
1. Density calculation
Step 1 – Calculate cubic volume
For imperial units (inches and pounds):
\[ \text{Cubic feet} = \frac{\text{Length (in)} \times \text{Width (in)} \times \text{Height (in)}}{1728} \]
Step 2 – Calculate density
\[ \text{Density (lb/ft}^3\text{)} = \frac{\text{Weight (lb)}}{\text{Cubic feet}} \]
For metric entries, the calculator converts cm and kg to inches and pounds internally, then uses the same formulas.
2. Map density to a base class range
Once density is known, the calculator maps it to a typical NMFC class range using the reference table above. For example:
- Density > 15 lb/ft³ → base class around 55–85
- Density 6–15 lb/ft³ → base class around 85–125
- Density < 4 lb/ft³ → base class 250–500
3. Adjust for handling and liability
The calculator then applies small adjustments to the base class to reflect handling and liability:
- Difficult handling may bump the estimate up one class step.
- Very fragile or high-value freight may bump it up further.
This does not replace the official NMFC item, but it gives you a more realistic planning number than density alone.
Worked example
Suppose you are shipping a pallet of boxed consumer goods:
- Length = 48 in
- Width = 40 in
- Height = 60 in
- Total weight = 1,200 lb (including pallet)
- Handling = Normal
- Liability = Medium
Step 1 – Volume
\[ \text{Cubic feet} = \frac{48 \times 40 \times 60}{1728} = \frac{115{,}200}{1728} \approx 66.7\ \text{ft}^3 \]
Step 2 – Density
\[ \text{Density} = \frac{1{,}200}{66.7} \approx 18.0\ \text{lb/ft}^3 \]
Step 3 – Base class
A density of about 18 lb/ft³ typically falls in the Class 70–85 range. With normal handling and medium liability, the calculator might estimate a class of 70 or 77.5.
Your actual NMFC item could still be slightly different, so always confirm with your carrier or 3PL.
Tips to lower your freight class (and cost)
- Increase density – Use smaller pallets or shorter stacks if you are shipping partially empty pallets.
- Improve packaging – Strong, stackable packaging can reduce handling risk and sometimes allow a lower class.
- Consolidate shipments – Combining multiple small shipments into one pallet can increase density.
- Use accurate measurements – Carriers reweigh and remeasure. Accurate data reduces reclass and rebill risk.
Limitations and important disclaimers
- This calculator is not an official NMFC tool.
- It does not assign NMFC item numbers.
- Carriers may use proprietary rules, FAK (freight-all-kinds) agreements, or negotiated pricing that override class.
- Always verify the final class with your carrier, 3PL, or NMFTA before tendering freight.
Freight class FAQ
How is freight class calculated?
Freight class is based on four factors: density, handling, stowability, and liability. This calculator computes density from your dimensions and weight, then maps it to a typical NMFC class range and adjusts it slightly for handling and liability. The official class, however, is defined by the NMFC item and confirmed by the carrier.
Is density the only thing that matters?
No. Density is very important, but not the only factor. Long, fragile, hazardous, or high-value freight can be assigned a higher class even if density is high. Conversely, some commodities have fixed classes regardless of density. Think of density as the starting point, not the final answer.
Can I use this estimate on my bill of lading?
You can use it as a guide, but you should not rely on it as the final class. Always confirm the NMFC item and class with your carrier, 3PL, or rating engine. If the carrier inspects your freight and finds a different class, they may reclass and rebill the shipment.
Do I need to include pallet dimensions and weight?
Yes. Freight class is based on the entire shipping unit, including pallet, crate, or other packaging. Measure the full footprint and height of the palletized load and use the total weight including pallet or crate when calculating density.
What if my freight is very long or can\u2019t be stacked?
Long freight, non-stackable pallets, or irregular shapes reduce trailer utilization and often justify a higher class. In the calculator, choose Difficult or Very fragile / special handling under Handling to see a more conservative estimate, then confirm with your carrier.