Decoding shipping costs: Understanding actual weight vs volumetric weight

When it comes to shipping costs in Canada, both businesses and individuals need to consider all factors that influence courier service rates. Many people assume that actual package weight is the only factor in calculating domestic and international shipping fees. However, volumetric weight—also known as dimensional weight—can have an equal or even greater impact on the final price.

By understanding the difference between actual weight and volumetric weight, you can make smarter packaging choices that help reduce unnecessary shipping charges. This guide explains how each weight type is calculated and how DHL Express Canada can support you in making more cost-effective shipping decisions for your parcels.

What is actual weight?

Actual weight is the most basic and straightforward method used to determine the weight of a shipment. It refers to the physical weight of a package as measured on a scale and is typically recorded in kilograms (kg) or pounds (lbs). This measurement is especially important when shipping dense or compact packages, where the size does not significantly exceed the weight.

To calculate the actual weight, courier companies simply weigh the parcel. However, for lightweight but bulky shipments, actual weight alone may not reflect the true cost of transporting the item. In such cases, volumetric weight becomes a more accurate cost indicator, especially in international shipping scenarios.

What is volumetric weight and why does it matter?

Volumetric weight, also known as dimensional weight, is a pricing method used by shipping carriers to account for the amount of space a package occupies relative to its actual weight. This measurement is especially important when shipping lightweight but bulky parcels, which can take up more room in delivery vehicles or aircraft.

Shipping providers like DHL Express use both volumetric and actual weight to calculate shipping charges—choosing the greater of the two to ensure fair pricing. For example, a large box filled with bubble wrap may weigh very little on a scale, but it occupies significant space. In such cases, the volumetric weight determines the shipping cost to prevent undercharging for large, lightweight packages.

What is a dim factor?

The dim factor (Dimensional Factor) is a constant used in calculating volumetric weight to standardize how international shipping carriers convert a package’s volume into its weight. Different shipping companies might use varying dim factors depending on their cost strategies and the types of items they typically transport. For reference, DHL Express uses a dim factor of 5000 when calculating its shipments.

DHL Express volumetric weight formula

The DHL Express volumetric weight formula helps shipping companies determine how much space a package will take up in the aircraft known as the dim factor. To calculate the volumetric weight, simply use DHL Express’s dimensional weight standard formula: length x width x height / 5000.

Actual vs volumetric weight: Which one favors you?

When determining shipping costs, the higher of the two weights—actual weight or volumetric weight—is used. This means neither one inherently favors the buyer1. 

For dense and heavy items, actual weight will likely result in higher shipping costs. Conversely, the volumetric weight may be the determining factor for lightweight but bulky items.

To save on shipping costs, it’s essential to understand the difference and choose packaging that minimizes the volumetric weight whenever possible. For example, using smaller or more compact packaging can reduce the dimensional weight, potentially lowering your costs.

How to integrate volumetric weight into your international shipping strategy

Integrating volumetric weight into your shipping strategy requires careful planning to ensure cost efficiency. 

First, collect the exact product dimensions for every item in your inventory. Ensure that your product listings include accurate measurements—length, width, and height—to facilitate reliable volumetric weight calculations for each shipment. Precise dimensions help avoid unexpected fees and support accurate forecasting of local and international shipping costs.

It is equally important to collaborate with your import or export shipping provider to understand their volumetric weight policies, including the dim factor they use for calculations. Each shipping provider may apply a different dim factor, directly impacting how volumetric weight is measured and billed. Familiarity with these policies enables you to make informed decisions about packaging and shipping methods.

Lastly, conduct regular reviews of your shipping data to identify patterns where volumetric weight significantly influences costs. Evaluate whether adjustments to packaging solutions or shipping practices could yield better efficiency. Regularly assessing packaging methods, shipment dimensions, and weight calculations allows you to identify cost-saving opportunities, reduce waste, and enable a more streamlined shipping operation.

Packaging tips to optimize volumetric weight

If volumetric weight exceeds the actual weight, shipping costs increase, especially for large yet light items. Optimizing packaging can lower dimensional weight, helping to reduce shipping rates and improve profitability.

Here are some tips to optimize volumetric weight:

• Select the correct box size: Using a box that is too large for the item increases the overall dimensions, resulting in a higher volumetric weight. Select a box that closely fits the size of your product to avoid unnecessary empty space.

• Use compact packing materials: Cushioning materials like thick foam or bulky bubble wrap can increase the size of a package without adding much weight. Consider alternatives such as crumpled paper, air pillows, or thin layers of protective padding. You can check out our guide to packaging materials to know more.

• Disassemble items whenever possible: If the items being shipped can be disassembled, it is advisable to do so. For example, furniture or machinery parts can be packed into smaller boxes when broken down, significantly reducing the package’s dimensions.

• Minimize product packaging: Retail products often come with their own packaging, which can add to the volumetric weight. Evaluate whether excess packaging, such as large product boxes or inserts, can be reduced or eliminated without compromising product safety.

• Consider poly mailers for soft items: Using poly mailers instead of traditional boxes can reduce volumetric weight for non-fragile items such as apparel or soft goods. Poly mailers conform to the shape of the item and have a lower profile than boxes, resulting in a smaller overall size and lower shipping costs.

• Reduce the need for double-boxing: Double-boxing is sometimes necessary for fragile items but significantly increases package size. Consider using a single, high-quality box with adequate padding instead where possible. If double-boxing is unavoidable, choose an outer box slightly larger than the inner box to minimize volumetric weight.

DHL Express: Your partner in cost-effective shipping

As a global leader in logistics and express delivery, DHL Express offers transparent and competitive international shipping rates by using advanced tools that calculate both actual weight and volumetric weight. With over 50 years of industry expertise and a global network of 100,000+ logistics professionals, we ensure fast, reliable, and door-to-door courier services—whether you're shipping within Canada or across the globe.

Take advantage of our expertise by exploring DHL Express shipping rates and services today. Open a DHL business account to unlock exclusive benefits, powerful shipping tools, and support tailored to your international shipping needs.