CargoSum
Guides

Freight Guides

Plain-language explainers for the freight math forwarders and shippers run every day — the formulas, the worked examples and the practical detail the tools don't have room to spell out.

2026-08-19

What Is CBM? Cubic Meters in Freight, Explained

How CBM is calculated, why carriers use it, and how it turns into the price you pay.

2026-08-19

Chargeable Weight: Why You Pay for Space, Not Just Kilograms

Actual vs volumetric weight, the 6000 and 5000 divisors, and how to avoid billing surprises.

2026-08-19

CBM to CFT Conversion for Shipping (Table + Formula)

Convert cubic meters to cubic feet and back: the exact factor, quick tables, and when each unit is used.

2026-08-19

How Many CBM Fit in a 20ft, 40ft, and 40ft HC Container?

Nominal vs practical container capacity: why a 67.7 m³ container carries about 55 CBM of real cartons.

2026-08-19

Volumetric Weight Explained: Why Light Cargo Costs More Than It Weighs

What dimensional weight is, the divisors carriers use, and five ways to reduce it.

2026-08-19

Freight Class Chart (NMFC Density Scale): All 13 Classes Explained

The NMFC density-based freight class table after the 2025 changes — class 50 through 400 by lb/ft³.

2026-08-19

How to Calculate Freight Density for LTL (Step by Step)

The exact pcf density method carriers use: measuring rules, multi-piece math, and reclass-fee pitfalls.

2026-08-19

Standard Pallet Sizes: GMA 48×40, EUR Pallet, and Regional Standards

Every major pallet standard with exact dimensions, load ratings, and which to use per destination.

2026-08-19

How Many Boxes Fit on a Pallet? Layer Patterns, Height Limits, Overhang

Calculate cartons per pallet: column vs interlocked stacking, overhang rules, and worked examples.

2026-08-19

How Many Pallets Fit in a 20ft and 40ft Container?

Exact pallet counts per container — EUR and GMA, single and double stacked — and the patterns behind them.

2026-08-19

Shipping Container Dimensions: 20ft, 40ft, 40HC, 45HC, Reefer, Open Top

Internal dimensions, door apertures, tare, payload, and capacity for every common ISO container type.

2026-08-19

How to Maximize Container Space: Loading Patterns That Add Real CBM

Practical container loading optimization: orientation, carton design, floor vs pallet, weight distribution.

2026-08-19

FCL vs LCL: The Real Break-Even Point (It's Lower Than You Think)

When to book a full container vs shared LCL space: cost structure, the 13–15 CBM break-even, and risk.

2026-08-19

Sea Freight vs Air Freight: Cost, Transit Time, and the Crossover

How sea and air freight really compare — billing units, door-to-door transit times, and choosing per shipment.

2026-08-19

Container Weight Limits: Payload, Road Rules, and VGM Explained

Gross, tare, net, payload — why road limits bind before the container does, and how VGM declaration works.