Why Verified Gross Mass (VGM) Matters for Safer Shipping

In logistics, a simple number can make the difference between a smooth journey and a costly disaster. One of these numbers is the Verified Gross Mass (VGM) of a shipping container.

The importance of VGM came into focus after several incidents of wrongly declared containers resulting in compromised vessels and near accidents. This highlighted that without accurate and reliable weight measurements, it’s difficult to load ships safely.

Throughout this article, we will discuss what the SOLAS Convention did to fix this issue, exactly what a verified gross mass is, and how to properly calculate it, as well as who the responsibilities fall on.

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What is Verified Gross Mass (VGM) in Logistics?

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Verified Gross Mass (VGM) is the certified, combined total weight of a shipping container, including cargo, packaging, bracing, and the container itself.

This measurement enables safe and predictable supply chains. Without this weight data, there’s more risk, as fuel calculations, overall freight costs, and correct vessel storage can be compromised.

VGM is a legal requirement as part of the SOLAS Convention (Safety of Life at Sea), which sets safety standards for shipping. These rules ensure that shippers provide the verified gross mass of the containers before the carrier is loaded onto the vessel to ensure there’s no overloading. This is a mandatory requirement; without a valid VGM, a container will not be allowed to be loaded onto a ship.

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Why VGM Matters for Maritime Safety and Beyond

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Before the amendments to SOLAS, undeclared container weights were a real threat, causing collapsed stacks, damage to the ship, or, in worst-case scenarios, capsizing and injury to workers. This also caused a threat to finances as shippers faced claims, fines, and delays with deliveries.

With these amendments, like requiring verified gross mass for all containers, the entire industry has shifted to a safety-first model. Though, for logistics partners, this doesn’t end with simply complying with the SOLAS laws; reporting accurate weights also feeds into:

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• Operational efficiency, as carriers can plan stowage with confidence.

• Cost control, to avoid penalties and extra storage charges.

• Sustainability, as precise weights help optimize fuel consumption

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VGM supports both the safety onboard vessels and the resilience of supply chains across the logistics industry.

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The Components of Verified Gross Mass

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To properly understand exactly how to be compliant and maintain efficiency throughout the supply chain, there are three essential components to understand:

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1. Cargo Weight: This refers to the weight of the cargo itself—all the products or items to be packaged inside the container.

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2. Container Tare Weight: This is the weight of the empty container. Usually, each container will display the tare weight on its door. Adding this measurement to the weight of the cargo will give you the gross weight.

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• Dunnage, Bracing, and Packaging: This includes the weight of any packaging materials like pallets, crates, or dunnage used to secure the cargo inside the container.

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It may be fairly simple to weigh these different elements to arrive at the final verified gross mass, but errors can still happen, from incomplete packing records to poor communications when using multiple logistics partners.

You can find a more in-depth look at different shipping weights in our dedicated article.

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How is VGM Calculated?

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There are two methods approved by SOLAS for calculating the verified gross mass, these are:

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Method 1: Weighing the packed and sealed container with the cargo inside by using a weighbridge; these are usually located at port terminals. You can also use this method along with the weight of the trailer if you know the verified weight. A calculation using this method looks like this:

VGM = Total weight from weighbridge – weight of trailer, including fuel (if used)

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Method 2: Weighing the cargo and contents of the container, including dunnage and packaging, first and then adding the tare weight of the container as indicated on the door. If using this method, many countries allow for a 2-5% buffer on the VGM to account for a potential loss from any wear and tear on the containers' journey to that point. This calculation looks like this:

VGM = Cargo weight + dunnage/packaging weight + container tare weight

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Note that across some countries like those in Southern Africa, method 1 may be challenging due to potential limits on access to certified equipment at ports, while method 2 requires a higher level of internal processes. This is why many shippers opt to work with logistics providers like Reload that bridge these gaps, offering access to reliable weighing infrastructure while supporting clients in staying compliant.

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Who is Responsible for Reporting Verified Gross Mass?

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The legal responsibility falls on the shipper of record. This is typically the cargo owner, or if using a freight forwarder, the responsibility of declaring VGM to carriers before loading the container shifts to them. In short, the responsibilities are as follows:

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• The shipper or freight forwarder calculates and declares VGM.

• The carrier must reject any containers without a valid or accurate VGM.

• Terminal operators rely heavily on timely and accurate declarations to plan loading sequences and keep supply chains moving.

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How to Properly Report VGM

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Verified gross mass must be transmitted to the carrier before the documentation cut-off point. Delays in this may mean that the container will be rolled onto the next sailing, which can disrupt supply chains and delivery times.

Digital transmission of VGM submissions is now possible with major carriers, which significantly speeds up the compliance. Many logistics partners have integrated VGM into their digital freight platforms, supporting clients with end-to-end VGM reporting solutions. The submission must include:

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• Booking number

• Container number

• The container's verified gross mass, along with the unit of measurement

• The name of the responsible person for the VGM declaration

• The authorized person's signature

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When verified gross mass is submitted in a timely and accurate way, some advantages ripple through the entire supply chain. For shippers, it reduces the risk of penalties and improves schedule reliability, for carriers, it ensures safer stowage as well as smoother operations, and for the terminal operators, it can reduce congestion and keep yard planning running smoothly.

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Final Thoughts: VGM as a Strategic Lever

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While at first Verified Gross Mass (VGM) may look like just another compliance step, it actually represents a much larger commitment to safety, accuracy, and resilience across the supply chain.

Globally, VGM has become a strategic opportunity, and at Reload Logistics, we see it as more than just a regulation. By offering VGM services alongside our freight forwarding and warehousing solutions, we help clients not only comply with international standards but also operate with confidence in complex markets, ensuring cargo is delivered efficiently, safely, and on time.

Contact us to discuss how we can support your business in staying compliant while creating a more efficient supply chain.

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FAQs

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What is VGM in the supply chain?

Verified Gross Mass (VGM) is the total weight of a packed shipping container, including the cargo, packing materials, and the container itself. It is a mandatory requirement for safe container transport by sea.

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What is VGM/verified gross mass?

Verified Gross Mass (VGM) is the confirmed and documented weight of an entire packed container. The weight must be verified by the shipper before the container is loaded onto a vessel, as per SOLAS (Safety of Life at Sea) regulations.

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Is VGM the same as gross weight?

In the context of shipping logistics, VGM is essentially the same as the gross weight of the entire container, including the container itself, the cargo inside, and any packaging.

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How do you calculate gross mass?

Gross mass is calculated by adding together the net weight of the cargo, packaging materials, and the empty container weight.

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Why is VGM needed?

VGM is required to ensure vessel safety and prevent accidents, comply with SOLAS regulations, and ensure efficient loading.

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How to submit VGM?

VGM submissions can be done either with electronic forms through the shipping line’s portal, or, if accepted by the carrier, by paper documentation.