Free Freight Class Calculator

What Is a Freight Class Calculator?

A freight class calculator determines the NMFC (National Motor Freight Classification) freight class for your shipment based on its density. Freight class is the single biggest factor in LTL (Less Than Truckload) shipping costs — the class assigned to your goods directly determines your shipping rate. This calculator takes your shipment's weight and dimensions, computes the density in pounds per cubic foot, and maps it to one of the 18 standard freight classes ranging from Class 50 (cheapest) to Class 500 (most expensive).

For ecommerce sellers shipping wholesale orders, pallet shipments, or inventory to warehouses, understanding freight class helps you accurately estimate shipping costs, negotiate better carrier rates, and avoid costly reclassification fees. Pair this with our CBM calculator for international shipments or landed cost calculator for full import costing.

How Is Freight Class Calculated?

Freight class is primarily determined by density, calculated as:

Density = Weight (lbs) ÷ Volume (ft³)
where Volume = (Length × Width × Height in inches) ÷ 1,728

The NMFC system uses 18 freight classes from 50 to 500. Higher density items get a lower freight class and cheaper rates, because carriers can fit more weight into their trucks. A dense pallet of electronics (Class 70–85) costs far less to ship per pound than a bulky pallet of pillows (Class 300–400). While density is the primary factor, carriers also consider stowability (how easily it fits), handling requirements (fragile, hazardous), and liability (value of goods) when assigning freight class.

Why Does Freight Class Matter for Ecommerce Sellers?

If you ship B2B orders, send inventory to Amazon FBA or other fulfilment centres, or manage wholesale distribution, freight class directly impacts your bottom line. Here's why it matters:

• Rate accuracy: LTL carriers price based on freight class. Knowing your class lets you get accurate quotes and compare carriers.
• Avoid reclassification fees: If you declare Class 70 but the carrier inspects and finds Class 100, you'll pay the higher rate plus a reclassification penalty.
• Packaging optimisation: Reducing volume (tighter packaging, smaller boxes) increases density and can push you into a lower, cheaper freight class.
• Cost forecasting: Accurate freight class data feeds into your break-even analysis and product pricing decisions.

NMFC Freight Class Breakdown

The 18 NMFC freight classes fall into three broad tiers:

• Classes 50–85 (High Density): Heavy, compact goods. Think metal parts, bottled beverages, machinery. These are the cheapest to ship.
• Classes 92.5–150 (Medium Density): Most general merchandise falls here — electronics, furniture, household appliances. Moderate shipping costs.
• Classes 175–500 (Low Density): Bulky, lightweight items. Clothing, mattresses, inflatable goods. Most expensive per pound because they take up truck space without adding weight.

How to Lower Your Freight Class

Since density drives freight class, increasing density is the key to lowering your shipping costs:

• Reduce packaging size: Use the smallest box that safely fits your products. Eliminate excess void fill and air space.
• Consolidate shipments: Combine multiple smaller boxes onto a single dense pallet instead of shipping separately.
• Flat-pack where possible: Disassembled furniture ships at a lower class than assembled furniture.
• Choose denser packaging materials: Corrugated cardboard with minimal air pockets beats foam inserts for density.
• Negotiate with carriers: High-volume shippers can sometimes negotiate a Freight All Kinds (FAK) rate that assigns a single class to all shipments, often lower than the standard classification.

Freight Class vs Dimensional Weight: What's the Difference?

Freight class (NMFC) applies to LTL (Less Than Truckload) shipments — pallets and large shipments handled by freight carriers like FedEx Freight, UPS Freight, and regional LTL carriers. Dimensional weight (DIM weight) applies to parcel shipping — individual packages shipped via UPS, FedEx, USPS, and couriers. Both penalise lightweight, bulky items, but they use different calculation methods. Use this calculator for LTL freight, and our CBM calculator for parcel dimensional/volumetric weight.