Question 1

What is NMFC freight class?

Accepted Answer

NMFC (National Motor Freight Classification) is a standardized freight classification system created by the National Motor Freight Traffic Association (NMFTA). It categorizes commodities into 18 freight classes ranging from 50 to 500, based on density, stowability, handling, and liability. Lower classes (50-70) have higher density and lower shipping costs, while higher classes (300-500) have lower density and higher costs.

Question 2

How is freight density calculated?

Accepted Answer

Freight density is calculated using the formula: Density (PCF) = Weight (lbs) ÷ Cubic Feet. First, calculate cubic feet by multiplying Length × Width × Height (in inches) and dividing by 1,728. Then divide the total shipment weight by the cubic feet to get pounds per cubic foot (PCF). This density determines your NMFC freight class.

Question 3

Why does freight class matter for LTL shipping?

Accepted Answer

Freight class directly affects your LTL (Less Than Truckload) shipping rates. Carriers use NMFC classes to standardize pricing - higher density shipments (lower class numbers) cost less per pound because they're more efficient to transport. Misclassifying freight can result in re-weighing fees, reclassification charges, and carrier rebilling that significantly increases your shipping costs.

Question 4

What is the most common freight class?

Accepted Answer

Class 70 and Class 85 are among the most common freight classes for general merchandise. Class 70 applies to items with density between 15-22.5 PCF, including many food products and auto parts. Class 85 covers densities of 12-13.5 PCF, common for crated machinery and electronics. Most everyday commercial goods fall between Class 60 and Class 125.

Question 5

How do I avoid freight class disputes with carriers?

Accepted Answer

To avoid disputes: 1) Accurately measure and weigh all packages before shipping. 2) Use the correct NMFC item number for your commodity. 3) Keep detailed records and photos of measurements. 4) Consider getting a binding classification from NMFTA for recurring shipments. 5) Use a density-based freight calculator to verify your class before shipping.

Question 6

What factors besides density affect freight class?

Accepted Answer

While density is the primary factor, NMFC classification also considers: Stowability (how easily it fits with other freight), Handling (special equipment or care needed), and Liability (value, fragility, perishability). Some items have fixed NMFC codes regardless of density due to these factors. Always check the NMFC tariff for your specific commodity.

Question 7

Can I ship different class items on the same pallet?

Accepted Answer

Yes, you can ship items of different classes together. Carriers typically classify mixed pallets by the highest (most expensive) class present, or they may calculate a blended rate. Some carriers offer 'FAK' (Freight All Kinds) agreements that assign a single negotiated class to all your shipments regardless of actual contents, which can simplify billing and reduce costs.

Question 8

What happens if my freight is reclassified?

Accepted Answer

If a carrier determines your freight was misclassified, they will re-rate the shipment at the correct class and bill you for the difference plus potential penalties. This 'rebilling' can add significant costs - sometimes 20-50% more than the original quote. To prevent this, always use accurate dimensions and weights, and verify your NMFC class before shipping.

Freight Class	Density Range (PCF)	Typical Commodities
Class 500	0 - 1 PCF	Lowest density, highest cost - ping pong balls, gold dust
Class 400	1 - 2 PCF	Very low density - deer antlers
Class 300	2 - 3 PCF	Low density - wood cabinets, tables
Class 250	3 - 4 PCF	Low density - bamboo furniture, mattresses
Class 200	4 - 5 PCF	Low density - auto sheet metal, aircraft parts
Class 175	5 - 6 PCF	Low-medium density - clothing, couches
Class 150	6 - 7 PCF	Medium density - auto parts, bookcases
Class 125	7 - 8 PCF	Medium density - small appliances
Class 110	8 - 9 PCF	Medium density - cabinets, framed artwork
Class 100	9 - 10.5 PCF	Medium density - boat covers, car covers
Class 92.5	10.5 - 12 PCF	Medium-high density - computers, monitors
Class 85	12 - 13.5 PCF	Medium-high density - crated machinery
Class 77.5	13.5 - 15 PCF	High density - tires, bathroom fixtures
Class 70	15 - 22.5 PCF	High density - food items, car parts
Class 65	22.5 - 30 PCF	High density - car accessories, boxed books
Class 60	30 - 35 PCF	Very high density - car parts, steel
Class 55	35 - 50 PCF	Very high density - bricks, cement, hardwood
Class 50	50 - 50+ PCF	Highest density, lowest cost - sand, gravel, nuts/bolts

NMFC Freight Class Calculator

Freight Class Calculator

Quick Dimension Presets

Package Dimensions

Shipment Weight

Classification Result

What Is an NMFC Class Calculator?

How to Calculate Freight Class Manually

Freight Density Calculation Example

Sample Problem: Calculating Class for 2 Boxes

Complete NMFC 18-Class Density Chart

Why Freight Class Matters for LTL Shipping

Accurate Quotes

Avoid Re-billing

Cost Optimization

Carrier Relationships

How to Avoid Carrier Re-billing Penalties

1. Measure Accurately

2. Use Certified Scales

3. Document Everything

4. Know Your NMFC Codes

5. Consider FAK Agreements

6. Optimize Packaging

7. Use a Freight Calculator

8. Request Binding Classification

About the National Motor Freight Traffic Association

Frequently Asked Questions

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