Accessorial Charges Calculator
Calculate freight accessorial charges including liftgate, inside delivery, appointment scheduling, and residential delivery fees for LTL shipments.
Freight Class Calculator
Determine NMFC freight class from package density in lbs per cubic foot. Map density ranges to classes 50 through 500 for LTL shipping rates.
lbs
in
in
in
Volume⧉
40.00
cubic feet
Density⧉
12.50
lbs per ft³
Freight Class⧉
Class 85
Based on density
Planning notes, formulas, and examples
About the Freight Class Calculator
Freight class is a standardized classification system used by LTL (less-than-truckload) carriers to price shipments. The National Motor Freight Classification (NMFC) system assigns classes from 50 to 500 based primarily on density, but also considering stowability, handling, and liability. Class 50 represents the densest, easiest-to-ship freight, while class 500 covers the lightest, most difficult freight.
Density is the most important factor in determining freight class. It is calculated by dividing the total weight of a shipment by its total cubic footage. Each density range maps to a specific freight class, and that class determines the rate per hundredweight (CWT) charged by the carrier.
This calculator takes your shipment weight and dimensions, computes the density in pounds per cubic foot, and maps it to the appropriate NMFC freight class. Knowing your freight class before requesting quotes helps you budget accurately and avoid reclassification surprises.
Use the result to compare operating scenarios, pressure-test assumptions, and rerun the model when volumes, rates, or service targets change.
When This Page Helps
Incorrect freight class is one of the most common causes of LTL billing adjustments. Carriers routinely inspect and reclassify shipments, leading to unexpected charges. By calculating your freight class upfront using density, you can ensure accurate quoting, avoid reclassification fees, and negotiate better rates for your actual freight profile.
How to Use the Inputs
- Enter the total shipment weight in pounds.
- Enter the length, width, and height of the shipment in inches.
- The calculator converts dimensions to cubic feet.
- View the computed density in pounds per cubic foot.
- See the mapped NMFC freight class based on density.
- Use this class when requesting LTL freight quotes.
Formula used
Volume (ft³) = (L × W × H) / 1,728
Density (lb/ft³) = Weight / Volume
Density-to-Class mapping:
≥ 50 lb/ft³ → Class 50
35–50 → Class 55
30–35 → Class 60
22.5–30 → Class 65
15–22.5 → Class 70
13.5–15 → Class 77.5
12–13.5 → Class 85
10.5–12 → Class 92.5
9–10.5 → Class 100
8–9 → Class 110
7–8 → Class 125
6–7 → Class 150
5–6 → Class 175
4–5 → Class 200
3–4 → Class 250
2–3 → Class 300
1–2 → Class 400
< 1 → Class 500Example Calculation
Result: Freight Class 100
Volume = (48 × 40 × 36) / 1,728 = 40 ft³. Density = 500 / 40 = 12.5 lb/ft³. A density of 12.5 lb/ft³ falls in the 12–13.5 range, but note standard mapping places 9–10.5 as class 100. At 12.5 this maps to Class 85. Actual mapping: 12–13.5 → Class 85.
Tips & Best Practices
- Always measure to the furthest point, including pallet overhang and packaging.
- Include pallet weight and dimensions in your measurement for palletized freight.
- Density is the primary but not the only factor — some commodities have fixed NMFC classes regardless of density.
- Document your freight with photos and measurements to dispute reclassifications.
- Higher density = lower class = lower rate. Consolidate shipments to increase density.
- Review your NMFC item numbers regularly — classifications are updated periodically.
NMFC Class System Overview
The National Motor Freight Classification system has been in use since 1936 and is the standard for LTL pricing in North America. It groups commodities into 18 classes based on density, stowability, handling difficulty, and liability risk. While density is the dominant factor for most freight, the system also considers whether items are fragile, hazardous, or difficult to load.
Density-Based vs Commodity-Based Classification
Many shippers can use density-based classification, where the freight class is determined solely by the weight-to-volume ratio. However, some products have commodity-specific classifications that override density. Always check the NMFC tariff for your specific commodity before assuming density-based pricing applies.
Tips for Lowering Your Freight Class
To achieve a lower (cheaper) freight class, increase the density of your shipments. Stack cartons tightly on pallets, use smaller packaging, and consolidate multiple items into single palletized units. Every improvement in density can move you to a lower class bracket and reduce your per-CWT rate.
Sources & Methodology
Last updated:
Frequently Asked Questions
NMFC freight class is a standardized system ranging from 50 to 500 that categorizes LTL freight for pricing. Lower classes represent denser, easier-to-handle freight and receive lower rates. The system is maintained by the National Motor Freight Traffic Association (NMFTA).
Density (weight per cubic foot) is the primary factor. The NMFC system defines density ranges for each class. For example, freight with 15+ lb/ft³ density typically qualifies for class 70, while 4-5 lb/ft³ density maps to class 200.
If a carrier inspects your shipment and determines a different class, they will adjust your invoice accordingly. This is called a reclassification or reweigh. The correction can be higher or lower, but is usually higher, resulting in additional charges.
No. While density-based classification covers many items, some commodities have fixed NMFC classes tied to their specific NMFC item number. Machinery, electronics, and hazardous materials often have fixed classifications.
The NMFTA maintains the official NMFC tariff database (ClassIT). You can search by product description or commodity type to find the specific NMFC item number and associated freight class for your products.
You cannot change the official NMFC classification, but you can negotiate the rate within a class. Some carriers offer FAK (freight all kinds) agreements that assign a single negotiated class to all your freight, simplifying pricing.
Classes 70, 85, and 100 are the most common in general manufacturing and distribution. These correspond to medium-density freight that fits well in standard LTL operations.
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