# What freight class is my shipment?

Computes the density of a less-than-truckload shipment (total weight ÷ total volume, in pounds per cubic foot) and its class on the NMFC 13-sub density scale in effect since July 19, 2025.

- Page: https://www.acalculator.org/logistics/freight-class-calculator
- JSON spec: https://www.acalculator.org/logistics/freight-class-calculator.json
- Version: eda03fb695d3

## Default answer

Example with the default inputs (Lines of pieces 1, Length 12 in, Width 12 in, Height 12 in, Weight 11 lb, Quantity 1): At 11 pounds per cubic foot, the shipment is freight class 92.5.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| lines | Lines of pieces | How many different kinds of piece the shipment has (1 to 5), each with its own size and weight. |
| length1 | Length | The length of one piece on line 1, packaging included. |
| width1 | Width | The width of one piece on line 1, packaging included. |
| height1 | Height | The height of one piece on line 1, packaging included. |
| weight1 | Weight | The weight of one piece on line 1, packaging included. |
| quantity1 | Quantity | How many pieces of this size and weight on line 1. |
| length2 | Length (line 2) | The length of one piece on line 2, packaging included. |
| width2 | Width (line 2) | The width of one piece on line 2, packaging included. |
| height2 | Height (line 2) | The height of one piece on line 2, packaging included. |
| weight2 | Weight (line 2) | The weight of one piece on line 2, packaging included. |
| quantity2 | Quantity (line 2) | How many pieces of this size and weight on line 2. |
| length3 | Length (line 3) | The length of one piece on line 3, packaging included. |
| width3 | Width (line 3) | The width of one piece on line 3, packaging included. |
| height3 | Height (line 3) | The height of one piece on line 3, packaging included. |
| weight3 | Weight (line 3) | The weight of one piece on line 3, packaging included. |
| quantity3 | Quantity (line 3) | How many pieces of this size and weight on line 3. |
| length4 | Length (line 4) | The length of one piece on line 4, packaging included. |
| width4 | Width (line 4) | The width of one piece on line 4, packaging included. |
| height4 | Height (line 4) | The height of one piece on line 4, packaging included. |
| weight4 | Weight (line 4) | The weight of one piece on line 4, packaging included. |
| quantity4 | Quantity (line 4) | How many pieces of this size and weight on line 4. |
| length5 | Length (line 5) | The length of one piece on line 5, packaging included. |
| width5 | Width (line 5) | The width of one piece on line 5, packaging included. |
| height5 | Height (line 5) | The height of one piece on line 5, packaging included. |
| weight5 | Weight (line 5) | The weight of one piece on line 5, packaging included. |
| quantity5 | Quantity (line 5) | How many pieces of this size and weight on line 5. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| freightClass | Estimated freight class | The class on the NMFC 13-sub density scale for the shipment density. |
| density | Density | Total weight in pounds ÷ total volume in cubic feet. |
| densityMetric | Density (metric) | The same density in kilograms per cubic metre. |
| range | Density range for this class | The density range of the class on the scale. |
| totalWeight | Total weight | The weight of all pieces. |
| totalVolume | Total volume | The volume of all pieces: length × width × height × quantity, added up. |
| nextClass | Density for the next lower class | The density at which the shipment would move to the next lower (usually cheaper) class. |

## Method

density = total weight (lb) ÷ total volume (ft³); class from the NMFC 13-sub density scale

## Assumptions

- Only density sets the class here. The NMFC also weighs stowability, handling and liability, and many items have their own class, so check the item in the NMFC before you ship.
- Measure each piece at its longest, widest and highest points, packaging and pallet included.
- For a shipment of several pieces, the density is the total weight ÷ the total volume.
- The scale is the 13-sub density scale that NMFTA Docket 2025-1 put in effect on July 19, 2025.

## Worked examples

1. lines = 1, length1 = 0.3048, width1 = 0.3048, height1 = 0.3048, weight1 = 4.535924, quantity1 = 1 gives density = 10, freightClass = 92.5, nextClass = 12. Source: NMFC 13-sub density scale (Docket 2025-1): 10 lb ÷ 1 ft³ = 10 lb/ft³, in "10 but less than 12", class 92.5.
2. lines = 1, length1 = 1.2192, width1 = 1.016, height1 = 1.2192, weight1 = 226.796185, quantity1 = 1 gives density = 9.375, freightClass = 100.
3. lines = 2, length1 = 1.2192, width1 = 1.016, height1 = 1.524, weight1 = 362.873896, quantity1 = 2, length2 = 0.6096, width2 = 0.6096, height2 = 0.6096, weight2 = 22.679619, quantity2 = 4 gives totalWeight = 816.466266, density = 10.887097, freightClass = 92.5.
4. lines = 1, length1 = 0.3048, width1 = 0.3048, height1 = 0.3048, weight1 = 22.679619, quantity1 = 1 gives freightClass = 50, range = 50 lb/ft³ or more.
5. lines = 1, length1 = 0.508, width1 = 0.508, height1 = 0.4572, weight1 = 11.339809, quantity1 = 3 gives freightClass = 125, range = 6 to under 8 lb/ft³, nextClass = 8. Source: NMFC 13-sub density scale (Docket 2025-1): 75 lb ÷ (3 × 7,200 in³ ÷ 1,728) = 75 ÷ 12.5 = 6 lb/ft³, in "6 but less than 8", class 125.

## FAQ

### What is freight class?

Freight class is a standardized classification system used in the LTL shipping industry to categorize commodities. The system, managed by the National Motor Freight Traffic Association (NMFTA), groups all goods into one of 18 classes (from 50 to 500) to create a uniform pricing structure for carriers and shippers. The density scale that sets a class from density alone uses 13 of them, from 50 to 400.

### What is an NMFC Code and how is it different from freight class?

While related, they are not the same. Every shippable commodity has both a freight class and a more specific NMFC code. Freight Class is a broad category (e.g., Class 70) that includes items with similar shipping characteristics. NMFC Code is a unique numeric identifier for a specific commodity within that class (e.g., automobile engines). The freight class gives a general estimate of cost, but the NMFC code is required on the Bill of Lading for precise identification and billing.

### How is freight class determined?

Freight class is determined by evaluating a commodity's 'transportability,' which is based on four key factors: Density (weight per cubic foot - the most significant factor), Stowability (how easily the item can be stored with other freight), Handling (ease of loading/unloading), and Liability (risk of damage or theft). This calculator focuses on density-based classification.

### What are the 18 freight classes?

The 18 freight classes are 50, 55, 60, 65, 70, 77.5, 85, 92.5, 100, 110, 125, 150, 175, 200, 250, 300, 400, and 500. Class 50 is for very dense, durable items and is the least expensive to ship, while Class 500 is for very low-density or high-value items and is the most expensive.

### How is freight class calculated?

Freight class is primarily determined by density (weight per cubic foot). The formula is: Density = Weight (lbs) ÷ Volume (cubic feet). Higher density items get lower class numbers and typically lower shipping rates. Since July 19, 2025, the NMFC density scale has 13 ranges: for example, 10 but less than 12 lb/ft³ is class 92.5. This calculator provides density-based estimates for planning purposes.

### What happens if I classify my freight incorrectly?

Using an incorrect freight class will lead to the carrier reclassifying your shipment, resulting in a corrected, higher invoice with added fees. It can also cause shipping delays, administrative burden, and may limit the carrier's liability if the shipment is damaged.

### How do I classify a shipment with mixed freight?

If a single pallet contains items of different freight classes, and you do not list each commodity separately on the Bill of Lading, the carrier will rate the entire pallet at the highest (most expensive) freight class present. To avoid this, you must itemize each commodity, its weight, and its class on the BOL.

### Why did my carrier reclassify my shipment?

The most common reason for reclassification is a discrepancy in the shipment's weight or dimensions, which leads to an incorrect density and, therefore, an incorrect class. Other reasons include an inaccurate commodity description or failure to account for special handling requirements.

### How can I lower my freight class and shipping costs?

The most direct way to lower your freight class is to increase your shipment's density. This is achieved through packaging optimization: using smaller boxes, eliminating empty space, and creating compact pallet configurations to reduce the shipment's overall volume for the same weight.

### Do stackable shipments get a better rate?

Yes, often they do. Stackable freight allows carriers to better utilize their trailer space. Because of this efficiency, many carriers offer better pricing or discounts for stackable shipments and may apply an upcharge for non-stackable freight.

### Do I need to know my NMFC code to use this calculator?

No. This calculator provides an estimated freight class based on density alone. It is a tool for planning and quoting. However, to complete the official Bill of Lading (BOL), you must identify the correct NMFC code for your specific commodity.

### Is the full NMFC database available to the public?

No, the official NMFC database is a proprietary, subscription-based tool called ClassIT®, which is managed by the NMFTA. Logistics professionals and high-volume shippers typically subscribe to this service.

### How do I measure my shipment accurately?

Never estimate. Measure the longest length, widest width, and tallest height of the fully packaged and palletized freight. Round up to the nearest inch. Include the weight of the product, packaging, dunnage, and pallet. Use a calibrated, certified freight scale for weighing.

### Should I estimate my shipment's weight and dimensions?

No, never estimate. Carriers rely on precise measurements and are required by the Department of Transportation (DOT) to adhere to strict weight limits. Any estimation will likely be caught during a carrier inspection and will result in re-class fees and delays.

### How do I ship hazardous materials?

Hazardous materials (Hazmat) are governed by a separate and strict set of regulations from the U.S. Department of Transportation (DOT). These items have specific classification codes, labeling, and handling protocols that supersede any density-based calculation. You must consult with a logistics expert specializing in Hazmat shipping.

### Can I optimize my packaging to reduce freight class?

Yes! Right-sizing boxes, using stackable configurations, and eliminating overhang can increase density and potentially lower your freight class. However, always balance density optimization with adequate protection to avoid damage claims.