What Is Volumetric Weight and How Is It Calculated?

Ravi runs a home decor and gifting business. While checking his courier bill, he notices that a cushion cover set weighing 1.2 kg on his scale has been billed at 8 kg. The box is much bigger than the product itself, but he doesn’t realize that this could be the reason for the higher charge.

The courier hasn’t necessarily made a mistake. The parcel may take up more space than its actual weight suggests, which is why the courier uses volumetric weight to calculate shipping charges.

So, how does volumetric weight work, and why does it matter for your shipping costs? Let’s break it down.

Volumetric weight is the weight a courier bills based on a parcel’s size instead of what the scale shows. Multiply length, width, and height in centimeters, then divide by 5000. Couriers charge whichever is higher, volumetric weight or dead weight.

What is volumetric weight?

Volumetric weight is the weight a courier calculates based on how much space a package takes up, rather than how much it actually weighs. 

Ravi had packed a lightweight product in a fairly large box. So when the courier bill showed a much higher weight than his scale, he was puzzled. The difference came down to volumetric weight.

Couriers look at the size of a parcel as well as its actual weight. This is called volumetric weight, and it’s calculated using the parcel’s length, width and height. So, even if your product is lightweight, a large box can lead to higher shipping charges than a smaller, heavier package.

Here are three terms to understand:

• Dead weight: The actual weight of your packed parcel, measured on a weighing scale.
• Volumetric weight: The weight calculated using the parcel’s length, width and height.
• Chargeable weight: The higher of the dead weight and volumetric weight. This is what the courier uses to calculate shipping charges.

To understand how these two weights affect your shipping bill, read our guide on volumetric weight vs dead weight.

How do you calculate volumetric weight step-by-step?

Ravi’s parcel weighed just 1.2 kg, so why was he charged for 8 kg? The answer was the size of the box. Couriers consider how much space a parcel takes up, not just what it weighs on a scale.

For most Indian domestic shipments, the volumetric weight is calculated using this formula:

Volumetric weight (kg) = (Length × Width × Height in cm) ÷ 5000

The divisor can vary by courier, so check which one applies to your shipment.

To calculate the Volumetric weight-

1. Measure the outside of the packed box, including any bulges or parts that stick out.
2. Round each measurement up to the next whole centimeter.
3. Multiply the three numbers to get the volume in cubic centimeters.
4. Divide by your courier’s divisor, usually 5000.
5. Compare with dead weight. The higher figure is your chargeable weight.

Run Ravi’s carton through it. At 50 × 40 × 20 cm, the volume is 40,000 cubic centimeters, and dividing by 5000 gives 8 kg. That beats the 1.2 kg on the scale, so 8 kg became his chargeable weight. The sample on Shipway’s volumetric weight calculator page shows the same logic, where a 30 × 20 × 15 cm box works out to 1.8 kg.

That is the whole volumetric weight calculation. The maths is easy. The hard part is doing it for every SKU before the parcel leaves the warehouse.

Which divisor do Indian couriers use?

Ravi’s next question was fair. Does every courier divide by 5000?

The divisor can vary from one courier to another. Most Indian domestic couriers use 5000, while some use 4000. Air shipments may use 6000, depending on the courier and service.

The divisor can change how much you pay for the same parcel. A lower divisor gives you a higher volumetric weight, which can increase your shipping cost. So, before choosing a courier based on its per-kg rate, check the chargeable weight and the total cost of shipping your parcel.

How does packaging affect shipping costs? 

Ravi checked a few more products from his catalog to see if the same issue was affecting his other shipments. He found that the size of the box could make a big difference to the weight used for billing, even when the products themselves were light. Here are a few examples using illustrative dimensions and weights.

Light and bulky SKUs such as apparel boxes, gifting sets, and home decor bill on size. Dense, compact SKUs such as nutrition jars and books usually bill on the scale. Ravi set a simple rule: if a SKU’s volumetric weight is more than double its dead weight, it goes on the fix list first. The cushion set and the boxed tee made it. The protein jar did not.

How much can volumetric weight add to your shipping costs?

Take a T-shirt as an example. Packed in a box, its volumetric weight comes to 1.8 kg. Put the same T-shirt in a poly mailer, and it drops to 0.45 kg.

If the courier bills in 500 g slabs, that means you pay for 2 kg with the box and just 0.5 kg with the mailer. That’s three extra slabs for the same product.

At Shipway’s starting rate of ₹19 per 500 g, the difference works out to at least ₹57 per order. The actual cost will depend on your courier and delivery zone, but it shows how much packaging can affect your shipping bill.

Now imagine shipping 300 similar orders every day. That adds up to 9,000 orders a month and could mean around ₹5.13 lakh in avoidable freight costs.

These figures are illustrative. Your actual savings will depend on your courier rates, weight slabs and packaging. For Ravi, the numbers were enough to rethink how his team packed orders the very next morning.

How can you reduce volumetric weight?

These are the five changes Ravi’s team made, in the order that paid back fastest:

1. Map every SKU to a box – Stock 4 to 6 sizes and print the box code on the pick list. One oversized carton for everything is the most common leak.
2. Use poly mailers for clothes and other non-fragile items –  A T-shirt that has a volumetric weight of 1.80 kg in a box comes down to 0.45 kg when packed in a poly mailer.
3. Choose a box that fits the product – Too much empty space means a higher volumetric weight. Use only as much packing paper or filler as needed to keep the product safe.
4. Pack soft products more compactly – Ravi repacks his cushion cover set in a 40 × 30 × 15 cm box, bringing its volumetric weight down from 8 kg to 3.6 kg. With billing in 500 g slabs, that reduces the billed weight from 8 kg to 4 kg. At the starting rate used in this example, the saving is ₹152 per order.
5. Start with your 20 most-shipped products –  Check their packaging and dimensions first. Small changes to the products you ship every day can noticeably reduce your overall shipping costs.

Just make sure you don’t compromise on product safety to save on shipping. Your packaging should fit the product well and still protect it during transit.

Your products still need enough protection to reach customers safely. A damaged order and the cost of sending a replacement can easily outweigh any shipping savings.

Why do weight discrepancies still happen?

Even after switching to smaller boxes, Ravi noticed that some shipments were still being billed at a higher weight than he expected. On checking, he found that the weight entered during booking was sometimes incorrect, or the team had entered the product dimensions instead of measuring the packed parcel. 

Measure the parcel after packing and keep a photo of the box along with its dimensions and weight. If the courier charges you for more than you expected, you can check the bill against your records and raise the issue with the details in hand.

Doing this for every order can be time-consuming. Shipway’s volumetric weight calculator uses the applicable divisor for each of its 20+ courier partners when calculating rates. It also sends real-time weight dispute alerts, making it easier to catch billing differences and follow up on them.

Also, the Weight Management Suite helps you pack smarter with AI, predict discrepancy risks, and get intelligent weight freeze suggestions.

How does a volumetric weight calculator help?

If you run an online store, checking the weight of every parcel before shipping can take up a lot of time. And if your products come in different sizes, it can be difficult to work out why some orders cost more to ship than others.

A volumetric weight calculator helps you figure this out quickly. Enter the length, width, height and actual weight of your packed parcel. The calculator shows you the volumetric weight and actual weight, so you can see which one the courier may use to calculate your shipping charges.

For example, your product may weigh just 1 kg, but if the box is large, its volumetric weight could be 3 kg. In that case, the courier may charge you for 3 kg instead of 1 kg. Checking this before shipping helps you estimate the cost and see if a smaller box could help bring your shipping expenses down.

You can try Shipway’s free volumetric weight calculator to check your products before dispatch. It takes only a few seconds and doesn’t require a sign-up.

Conclusion

If you sell lightweight products in large boxes, volumetric weight can add quite a bit to your shipping bill. Check your packaging, measure parcels after packing, and make sure you understand how your courier calculates the chargeable weight. These small checks can help you avoid paying more than necessary.

Ravi still goes through his courier bill every Monday. The difference is that he now understands why some parcels cost more to ship and knows what to check when a charge seems too high.