Freight Class Calculator

Q: What does PCF stand for?

PCF stands for pounds per cubic foot . 2 It is the unit used to measure freight density. You get it by dividing the total weight of a piece in pounds by its total volume in cubic feet.

Q: Should I measure the pallet or just the product?

Measure the entire shipping unit , including the pallet. 2 If your product sits on a pallet and is wrapped or banded to it, measure the full length, width, and height from the bottom of the pallet to the top of the load. Include the pallet weight too.

Q: What if my shipment is not a perfect box shape?

Carriers measure the longest, widest, and tallest points of your shipment. 2 Even if it is round or oddly shaped, they treat it as a rectangular box using those maximum dimensions. Measure the same way for the most accurate class estimate.

Q: Can my freight class change after I ship?

Yes. Carriers can inspect and re-measure your shipment. If the actual dimensions or weight differ from what you listed, they may reclassify it and charge you a higher rate plus a reclassification fee. Always measure carefully before shipping.

Q: What is the difference between freight class and NMFC code?

An NMFC code is a number assigned to a specific type of product, like furniture or electronics. The freight class is the shipping category (50 to 500) tied to that code. Some NMFC codes have a fixed class, while others let the class change based on density. 2

Q: How many steps are on the NMFC density scale?

The NMFC's standard density scale has 13 steps : classes 400, 300, 250, 175, 125, 100, 92.5, 85, 70, 65, 60, 55 and 50. 1 The scale was expanded from 11 steps to 13. 2 The change took effect on July 19, 2025. 1

Freight Class Calculator

Introduction

Freight class determines how much you pay to ship items by LTL (less-than-truckload) carriers. Under the National Motor Freight Classification (NMFC), the standard density scale assigns a class from 50 to 400 based on your shipment's density, which is its weight divided by its volume.¹ A lower class means a lower shipping cost, and a higher class means a higher cost.

This Freight Class Calculator makes it simple to find your shipment's class. Just enter the length, width, height, and weight of your item, and the tool does the rest. It calculates the volume in cubic feet, finds the density in pounds per cubic foot (PCF), and matches it to the class on the NMFC's standard density scale. You can use US or metric units, and the calculator handles the conversion for you.

Knowing your freight class before you request a shipping quote helps you plan costs, avoid billing surprises, and compare carrier rates with confidence. Use the calculator below to get your result.

How to Use Our Freight Class Calculator

Enter your shipment's size, weight, and number of pieces below. The calculator will find your freight density and give you the correct NMFC freight class.

Unit System: Pick US/Imperial (inches and pounds) or Metric (centimeters and kilograms). If you switch units after typing in numbers, the calculator converts them for you.

Length: Type the length of one piece of your shipment. Use inches for US or centimeters for Metric.

Width: Type the width of one piece of your shipment. Use inches for US or centimeters for Metric.

Height: Type the height of one piece of your shipment. Use inches for US or centimeters for Metric.

Weight: Type the weight of one piece of your shipment. Use pounds for US or kilograms for Metric.

Number of Pieces: Type how many identical pieces are in your shipment. This must be a whole number of 1 or more.

Calculate: Click the Calculate button to see your results. You will get your estimated freight class, density in pounds per cubic foot, volume per piece, total volume, and total weight.

Reset: Click the Reset button to clear all fields and start over with the default values.

What Is Freight Class?

Freight class is a number assigned to shipments that move by LTL (less-than-truckload) carriers. The National Motor Freight Traffic Association (NMFTA) publishes the NMFC. Its standard density scale, in effect since July 19, 2025, has 13 steps from class 50 to class 400.¹ These classes help carriers decide how much to charge for shipping your goods.

How Is Freight Class Determined?

The most common way to find your freight class is by calculating density. Density is how much something weighs compared to how much space it takes up. You measure it in pounds per cubic foot (PCF). A heavy, small item has high density and gets a lower class number. A light, large item has low density and gets a higher class number. Lower class numbers mean lower shipping costs.

How to Calculate Density

First, multiply the length, width, and height of your shipment in inches. Divide that number by 1,728 to get cubic feet.² Then divide the weight in pounds by the cubic feet.² The result is your density in PCF. This calculator does all of that math for you instantly.

Why Freight Class Matters

Carriers use freight class to set their rates. If you pick the wrong class, you could get hit with extra fees or a reclassification charge. Knowing your correct freight class before you ship helps you get accurate quotes, avoid surprise costs, and plan your budget. It also helps you compare rates between different LTL carriers fairly. When planning your overall supply chain, understanding lead time alongside freight costs gives you a more complete picture.

Things to Keep in Mind

Density is not the only factor that can affect freight class. Some items have a class set by the NMFC for what the product actually is. Items with handling, stowability, or liability concerns, such as fragile or hazardous goods, get a class based on the commodity rather than the standard density scale.² Always check the specific NMFC classification for your commodity when possible. This calculator gives you a density-based estimate, which works well for most standard shipments. For construction materials like concrete or steel, knowing the exact weight beforehand makes your freight class calculation more accurate.

Formulas used

Volume per Piece (cubic feet) ²

V_{piece} = \frac{L_{in} \times W_{in} \times H_{in}}{1728}

Total Volume

V_{total} = V_{piece} \times N_{pieces}

Total Weight

W_{total} = W_{piece} \times N_{pieces}

Density (Pounds per Cubic Foot) ²

\text{PCF} = \frac{W_{piece}}{V_{piece}}

Freight Class Determination ¹

\text{Class} = f(\text{PCF}) \quad \text{via NMFC density-based tier lookup}

Frequently asked questions

What is density in freight shipping?

Density is how heavy something is compared to the space it takes up. In freight shipping, it is measured in pounds per cubic foot (PCF). You find it by dividing the weight of your item in pounds by its volume in cubic feet. Higher density means a lower freight class and lower shipping cost.

What does PCF stand for?

PCF stands for pounds per cubic foot.² It is the unit used to measure freight density. You get it by dividing the total weight of a piece in pounds by its total volume in cubic feet.

Why is class 50 the cheapest and class 500 the most expensive?

Class 50 items are heavy and small, so they are easy and efficient for carriers to move. Class 500 items are light and bulky, taking up a lot of truck space without adding much weight. Carriers charge more when items use space without enough weight to fill the truck efficiently.

Should I measure the pallet or just the product?

Measure the entire shipping unit, including the pallet.² If your product sits on a pallet and is wrapped or banded to it, measure the full length, width, and height from the bottom of the pallet to the top of the load. Include the pallet weight too.

What if my shipment is not a perfect box shape?

Carriers measure the longest, widest, and tallest points of your shipment.² Even if it is round or oddly shaped, they treat it as a rectangular box using those maximum dimensions. Measure the same way for the most accurate class estimate.

Can my freight class change after I ship?

Yes. Carriers can inspect and re-measure your shipment. If the actual dimensions or weight differ from what you listed, they may reclassify it and charge you a higher rate plus a reclassification fee. Always measure carefully before shipping.

What is a reclassification fee?

A reclassification fee is a charge a carrier adds when they inspect your shipment and find it belongs in a different freight class than what you declared. This usually means you underestimated the size or overestimated the weight, resulting in a higher class and extra cost.

What is the difference between freight class and NMFC code?

An NMFC code is a number assigned to a specific type of product, like furniture or electronics. The freight class is the shipping category (50 to 500) tied to that code. Some NMFC codes have a fixed class, while others let the class change based on density.²

How many steps are on the NMFC density scale?

The NMFC's standard density scale has 13 steps: classes 400, 300, 250, 175, 125, 100, 92.5, 85, 70, 65, 60, 55 and 50.¹ The scale was expanded from 11 steps to 13.² The change took effect on July 19, 2025.¹

Why did my freight class go up when I used a bigger box?

A bigger box increases your shipment's volume without adding weight. This lowers the density, which pushes you into a higher freight class. Higher classes cost more to ship. Use the smallest box that safely holds your product to keep your class low.

Does the number of pieces change the freight class?

No. Under the NMFC, density is worked out for each handling unit, unless the shipping papers show only a total weight for all the units, in which case the total weight and total cube may be used.² The number of pieces affects your total volume and total weight, which matter for the shipping quote, but the class itself comes from per-piece density.

What if my item has a fixed NMFC class?

Some products have a fixed class set for the commodity itself because of handling, stowability, or liability concerns, rather than by the standard density scale.² This calculator gives a density-based estimate. Check the NMFC tariff for your specific commodity to confirm if a fixed class applies.

Sources

Disposition Bulletin 1371: Notice of Disposition – Docket 2025-1. National Motor Freight Traffic Association. 2025;p. 1 (effective date); p. 2 (13-subprovision density scale). Accessed September 29, 2026.

2025 NMFC Changes (FAQ). National Motor Freight Traffic Association. 2024;Pg. 3-6. Accessed September 29, 2026.

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