I have an embarrassing story to tell. My son requested a comforter for Christmas this year, and picked out an exceptionally fluffy one online. He was flying home for Christmas, so I had the comforter shipped to myself (free shipping, yay!), knowing I’d have to ship it to his house after the holidays. What I wish I’d known was that, due to the size of the box, it would cost me almost $100 to ship it to his house — nearly as much as the price of the comforter!

I’m embarrassed because I should have known better. Knowing everything I know about dimensional weight and ecommerce shipping, I should have shipped it directly to his house. But it was too late at that point. Then, because I was in a hurry, I just took the hit, rather than searching for a workaround. Was there anything I could have done to reduce the cost? And how in the world did that ecommerce company manage to ship it to me for nothing?

Today, we’re going to discuss how package weight affects ecommerce shipping rates. We’ll explore how to ship heavy products, how to avoid the dreaded DIM weight charge for lightweight products, and other ways to work around the weight factor and lower your shipping costs. Let’s get started!

How are Ecommerce Shipping Costs Calculated?

If you want to lower your shipping costs, you need to know how shipping cost is calculated and what extra costs (surcharges) might affect your final rate. All shipping carriers take the following four things into account when calculating a shipping rate.

1. Weight (actual weight of the package in pounds or kg)
2. Dimensional weight (a formula involving package size and weight)
3. Shipping zones (how far it has to go)
4. Speed (how fast the customer wants it)

Most carriers have carefully calculated standards for what they consider a normal range for size and weight. Any package that falls outside of the acceptable numbers for size and weight is charged a premium. To set the shipping rate, the carrier weighs the package, then calculates the dimensional weight. It uses the larger of the two, in conjunction with the shipping method and the number of shipping zones it’s crossing, to arrive at the base shipping rate. Surcharges may be added on top of this rate for exceptionally large, heavy, or fragile packages.

How Heavy is Too Heavy?

Heavy, oversized packages cost the carrier more (in terms of special handling requirements, cubic space, and fuel costs) and are charged accordingly.

• USPS:  packages up to 70 pounds may be shipped via USPS Priority Mail, Priority Mail Express, or Ground.
• FedEx:  packages up to 150 pounds may be shipped via FedEx Ground; packages over 150 pounds qualify for FedEx Freight shipping rates. If the actual weight is over 50 lbs. a surcharge applies for US Express and US Ground services. If the actual weight is over 70 lbs., a surcharge applies for International Express and International Ground services.
• UPS:  a package is considered oversized if it is over 150 pounds it will incur a surcharge and may be subject to DIM weight.
• DHL:  any package that exceeds 70 kg (155 pounds) is considered oversized and is subject to a surcharge of $89.

How Big is Too Big?

Lightweight, oversized packages cost less to move, but fewer of them fit on a truck or plane. The more packages a shipping carrier can fit into a trailer or cargo hold, the more money they’ll make on a trip across the country. If a package is large but lightweight, and the carrier were to charge by weight alone (like they all did prior to 2015), they would lose money. That’s why, since 2015, carriers have used what’s called a dimensional weight formula (or, in the case of DHL, volumetric weight formula) to calculate shipping rates for lightweight, oversized packages. It’s essentially a penalty for taking up too much space. As mentioned above, they may also add an oversized surcharge or handling surcharge over and above the shipping rate.

• USPS:  packages over 1 cubic foot in volume are automatically subject to DIM weight; packages over 2 cubic feet, will trigger an additional nonstandard volume fee; if the longest dimension is over 108 inches, or its combined length and girth (L + 2W + 2H) is over 130 inches, it will also trigger a flat oversized fee.
• FedEx:  2-day services are limited to packages up to 150 lbs., up to 119 inches in length, and up to 165 inches in length plus girth. An oversize charge of $90 applies to packages greater than 96 inches in length or 130 inches in length and girth. The shipping rate is then based on the greater of the package’s actual rounded weight or dimensional weight, subject to a 90-lb. minimum billable weight. FedEx Express International shipments are not subject to a 90-lb. minimum billable weight. As of January 1, 2024, any Express or Ground package that measures greater than 48 inches along its longest side; measures greater than 30 inches along its second-longest side; or measures greater than 105 inches in length and girth will incur an additional handling surcharge.
• UPS:  any package over 108 inches in length, or 165 inches in girth it will incur a surcharge and may be subject to DIM weight.
• DHL:  a package that has any one dimension that exceeds 120 cm (47.24 inches) is considered oversized will incur a surcharge of $89 and may be subject to DIM weight.

How to Calculate DIM Weight

1. Measure the length, width, and height of your package, using the longest point for each side.

2. Multiply all 3 measurements to get the cubic size of your package.

3. Divide the cubic size by the DIM factor (or, in the case of DHL, density factor) and round up to the nearest inch or centimeter.

Check out ShipMonk’s Dimensional Weight Calculator.

What is a DIM factor, you ask? The DIM factor/density factor is simply a number set by shipping carriers to represent the cubic inch per pound of a package. Each carrier sets its own DIM factor/density factor to calculate dimensional weight.

but the major carriers use one of the following:

• FedEx, UPS, and DHL Express: 139
• DHL eCommerce* and USPS*: 166

* Note: For DHL and USPS, DIM weight only applies if the package is larger than 1 cubic foot. Different DIM factors may be used for international shipping.

The higher the DIM factor, the lower the DIM weight — the number used to calculate the final cost.

Workarounds

It’s not rocket science. To save money on shipping, you have to lower one or more of the four factors used to calculate the rate: weight, volumetric weight, shipping zones or speed. In other words, aim for making it lighter, making it smaller, shortening the distance it has to travel, or moving it slower. Then, make sure you’re using the right shipping company for the job, and negotiate rates whenever possible.

Make it Lighter

When shipping heavy products, it’s important to prevent movement and weight shifting during transport while keeping the materials as light as possible. The objective is to stay below the weight surcharge limits listed above.

• Use bubble wrap, air pillows, or an eco-friendly alternative as dunnage.
• Split orders into two or more packages if the combined contents pushes it over the weight limit.
• Invest in precision-designed packaging that provides lightweight protection without adding a great deal of size. While custom designed packaging can be expensive, it may save you money in the long run, by eliminating the need for an exterior shipping box and packing materials.

Of course, if your product, sans packaging, is already above the weight limit there’s not much you can do to make it lighter. You’ll have to explore one of the other cost-cutting methods.

Make it Smaller

Shrinking the size of your package is much easier than losing weight, if you’re open to experimenting.

• Custom packaging can also work miracles when it comes to reducing the size of your shipments. Can the product be disassembled, even a little bit, to make it more compact for shipping and reassembled by the consumer? Can oddly shaped parts be shipped together, but in separate packages? If so, it’s worth working with your manufacturer to design custom packaging.
• Your fulfillment center or 3PL can also help determine the best way to package your products for the most affordable shipping. For example, ShipMonk runs every SKU through a dimensional scanner during the receiving process. As orders come in, our systems automatically determine the best outer packaging to safely contain all the items in the order, then choose the best shipping company based on price, reliability and availability.

• Orders that contain multiple products can be divided into two or more smaller packages, rather than one excessively large package.
• For items that are full of air (like my son’s comforter) consider using vacuum sealed packaging to suck the air out and reduce its overall size. This same technique has transformed the mattress industry, so why not your product?

Shorten the Distance

There are several ways to shorten the distance your products have to travel between your fulfillment center and the customer’s delivery address.

• Distribute inventory across the country (and around the world) by using a 3PL that owns and manages multiple locations. Inventory can be shipped in bulk to the warehouses, taking advantage of freight shipping rates. Orders are then fulfilled from the facility closest to the destination, and can take advantage of local or regional carrier pricing.
• Allow package pickup at a brick-and-mortar store or a carrier’s retail location, such as a FedEx or UPS store.
• These same techniques can reduce shipping costs on returns. Utilize local dropoff locations, where returned items can be consolidated into bulk packages that will cost you less to ship.

Slow Your Roll

Given the choice, many customers prefer slow and affordable over expedited and expensive shipping.

• Ground shipping is going to be the least expensive way to ship any large or heavy package. The tradeoff is that it’s going to be a lot slower.
• If the customer demands faster shipping, they should have the option to pay an expedited shipping fee. Give them a choice, but leave it up to them. By the way, distributing your inventory with a 3PL such as ShipMonk enables you to offer customers 2-day delivery to any locations in the US.

Shop Around

Once you’ve gotten your package down to its lightest, slimmest fighting weight, shop around for the carrier that offers the best business rates.

• Some shipping carriers are better than others when it comes to heavy or large packages. Because of the 166 DIM factor, USPS and DHL are the best option if your package is subject to DIM weight.
• Consider DHL Freight for large packages and affordable international shipping options.
• Consider USPS if your package weighs less than 70 pounds, or fits into one of their flat rate shipping boxes.
• Consider FedEx if your package weighs between 70 and 150 pounds, and when speed is more important than price.
• Consider FedEx Freight if you’re shipping large volumes of heavy or oversized items.
• Try to negotiate a flat rate or reduced surcharges if you’re shipping a large number of oversized packages, or if your dimensions fall within an inch or two of accepted limits.

Get Help

The right fulfillment partner can do much of the legwork for you, and help you avoid excessive shipping charges from the start. If the idea of calculating shipping charges for every order has your head spinning, consider partnering with a 3PL like ShipMonk.

• ShipMonk welcomes custom packaging, so there’s no need to put your beautifully branded box into another box just for shipping.
• We own and manage 12 fulfillment centers across the US, Canada, Mexico, the UK, and Europe. You can distribute your inventory far and wide, reducing shipping speed and cost.
• We can manage your returns and reverse logistics as well as order fulfillment.
• We offer room for growth. No matter how large your merchandise or how fast you’re growing, you can’t outgrow us.
• Our fulfillment centers feature industry leading automation that takes the guesswork out of packaging and shipping large or heavy items.
• Our extensive, carrier-agnostic Virtual Carrier Network automatically chooses the right shipping carrier for on time, affordable delivery.

Need help managing ecommerce fulfillment and shipping for large or heavy items? Contact ShipMonk and let us put our workarounds to work for your business. As one of America’s top companies for the fourth year in a row, we’re not only great at order fulfillment; we’re pretty good at solving problems.