The Smart Seller’s Guide to Choosing the Right Shipping Carrier

Scenarios 

First, let's go over the different attributes of items you may need to send and various shipping scenarios. We’ll cover the carriers we would recommend for;

• Light and small items
• Light but bulky items
• Heavy items
• Heavy and bulky items
• Items that need special handling

Small and light items (shipments from under 1 lb. up to around 10 lbs.)

Carriers typically charge based on weight and zone (distance travelled). Small and light items are desired differently by individual carriers for several reasons.

• Typically, the lowest revenue shipments for carriers. This means that you usually need to have volume in order to get the best rates from carriers on these types of items.
• Carriers have certain fixed costs regardless of size or weight.
• Results in the lowest margin for the carrier, although it makes up a large portion of overall shipments.
• One positive thing for carriers is that they do not take up much room in the system.

How the individual carrier works to win small and light volume will depend on how their specific system is set up.

Here are several carriers with notes on how they approach small and light shipments:

USPS

Sorting systems and smaller delivery vehicles are geared for small and light packages. USPS targets these types of shipments with attractive rates for both Ground Advantage and Priority Mail. The postal services have very few surcharges compared to most carriers, which can also play into the decision.

• Strong option due to infrastructure optimized for small/light deliveries.
• Offers Ground Advantage and Priority Mail with competitive pricing and very few surcharges.

Consolidators

Consolidators such as DHL eCommerce, OSM, Ascendia, and others have historically gone after small and light shipments. Their systems and automation are also geared for smaller packages. Most move packages through their network and then hand off to another carrier (USPS, Regional and/or Local Carriers) for final delivery. There has been some shake up in 2025 with changes for the under 1 lb. shipments, but in general consolidators remain a strong choice for small and light shipments if you can meet the minimum number of shipments for daily pickup.

• Designed to handle high volumes of small/light shipments with efficient handoffs to USPS or local carriers for final mile delivery.
• In 2025, changes to sub-1 lb. pricing have shaken up the landscape, but consolidators remain a cost-effective option if you meet minimum volume requirements for pickup.

National Carriers UPS and FedEx

Grouped together because they offer service to all addresses and their rates are often similar for their Ground and Deferred Ground service level. Both are strong when looking at time in transit, but you must be aware of minimum charges, and applicable surcharges, which will affect the true net of what you are charged. Pricing for shipments with UPS and FedEx will also be tied to how much you spend with them. Always be aware of your true cost when making value comparisons.

• Provide nationwide coverage and fast time-in-transit, but their rates are less competitive for low-weight shipments unless you're leveraging strong discounts.
• Watch out for minimum charges and surcharges that can erode cost-effectiveness on small orders.

Regional Carriers

Regional Carriers such as GLS, OnTrac, LSO and others can be a good option for packages that are within their delivery network. They will have strong time-in-transit performance and typically provide lower minimums than national carriers. Since they do not deliver to all addresses, you must keep in mind how using a regional carrier for some of your shipments may affect your tiers (pricing/discounts based on the amount spent) with the national carriers.

Light but bulky items

These are shipments where the dimensional (DIM) weight is greater than the actual weight. Common examples include pillows, foam items, lightweight appliances, or boxed toys. These items often appear inexpensive to ship based on scale weight, but are penalized by carriers for taking up more space in transit.

Key Considerations:

• DIM weight is calculated using the formula: (Length × Width × Height) ÷ DIM Factor
• Carriers apply different DIM factors and rules. The lower the DIM factor, the higher the billed weight.
• Understanding when and how each carrier applies DIM pricing is essential to avoid surprises.

A few carrier rules: USPS:

• DIM weight is not applied for packages under 1 cubic foot (L × W × H < 1,728 in³).
• Offers Cubic Pricing for Ground Advantage (under 1.0 cu ft) and Priority Mail (under 0.5 cu ft).
• Can ship up to 20 lbs. at the same rate if package size qualifies—great value for medium-sized lightweight items.

DHL eCommerce:

• DIM weight does not apply for packages under 1 cubic foot or under 1 lb.
• DIM Factor: 166, making it more favorable than national carriers.
• A smart option for lightweight, voluminous items—as long as you meet daily volume minimums.

GLS:

• DIM weight only applies to packages over 3 cubic feet—generous compared to most carriers.
• DIM Factor: 166.
• Ideal for merchants shipping light/bulky items within the Western U.S. region.

UPS and FedEx:

• Apply DIM weight to all packages if it exceeds actual weight.
• Use a lower DIM factor of 139, resulting in higher billed weights compared to other carriers.
• Great for reliability and reach, but can be costly unless you have strong negotiated discounts or use alternative packaging strategies.

Heavier items – 5 lbs. to 150 lbs.

Heavy items are more expensive to send out, so it’s important to leverage your carrier relationships and stay on top of surcharges. Here are a few carrier notes:

USPS:

• Rates are competitive for heavier items up to around 20 lbs, particularly with Ground Advantage.
• Priority Mail offers decent rates when packages are under 0.5 cubic foot, leveraging size-based pricing.

FedEx and UPS:

• The go-to carriers for 5–150 lbs., offering full U.S. coverage and reliable weekday delivery.
• Strong contenders for weekday deliveries. However,
• A strong option for 70–150 lb. shipments, particularly when supported by negotiated rates. Most competitive for shipments 5 pounds to 70 pounds.
• Be aware of minimum charges, surcharges, and delivery area fees—these can significantly impact final costs if unmanaged.

Heavy and bulky items

These are shipments where both the actual weight and the size of the package contribute significantly to shipping costs. Examples include furniture, large equipment, oversized consumer goods, or combined product bundles. They often exceed the standard parcel size and weight limits for typical small-package networks.

Key Considerations:

• Expect higher base rates and surcharges, including additional handling, large package fees, or non-conveyable item fees.
• Understanding dimensional weight, threshold limits, and when to switch from parcel to freight is critical.

Carrier information:

• UPS and FedEx: Both can deliver items up to 150lbs, but you’ll need to watch out for surcharges and thresholds at which prices spike.
• LTL Freight: This service can be done through various carriers, and may be necessary if your items weigh more than 150lbs.

Items that need special handling

Some shipments require special handling due to their contents—whether fragile, perishable, live, or regulated. Items like glassware, temperature-sensitive goods, and live animals demand extra care in packaging and service selection, and not all carriers are equipped to handle them reliably.

While USPS is surprisingly accommodating with certain live shipments, most sensitive or high-value items will benefit from using services that offer enhanced tracking, faster delivery, or additional handling protections.

Regions (US only) 

Next, let’s look at a breakdown of carrier performance by region.

Concentrated demand

If most of your consumer demand is concentrated in one area, you can consider using a regional carrier that focuses on that area. For example;

• Western States: GLS and OnTrac are examples of regional carriers that are strong in the West.
• Southern States: LSO is strong in Texas and the surrounding states.
• Eastern States: OnTrac also provides service in the East with its fairly recent acquisition of Lasership.
• There are many other Local and Regional Carriers who can help, so be sure to do your research for your specific area.

Nationally widespread demand

If the demand for your items are spread out across the country, we recommend going with any of the national carriers such as USPS, UPS, FedEx, Amazon Shipping, and DHL eCommerce depending on what your items are like (light and small, heavy and bulky, or something else). The optimal solution, if at all possible, will be a combination of carriers for the different types of shipments you have. Use our guide above to find the best fit for your SKUs.

International markets

• UPS and FedEx both have international expedited options for sending items globally that need to get there quickly.
• If shipments aren’t as urgent and you or your customers are willing to wait, USPS, DHL eCommerce, ePost Global, and others have good options for lightweight international shipments.

In conclusion, you must understand your shipments and how they match up with offerings from different carriers to find the best balance for your shipping between, cost, time-in-transit, and customer experience.

About the Author

Carl Hutchinson is the co-founder and chief analytics officer of iDrive Logistics. With over 37 years of experience in the industry, Carl is responsible for operations, client management, and carrier relations at iDrive. Founded in 2008 by small parcel industry leaders, iDrive Logistics provides shipping and fulfillment solutions for top ecommerce brands and 3PL fulfillment warehouses. With 100 years of collective small parcel experience and strong industry connections, iDrive’s innovative shipping solutions empower 3PLs and eCommerce brands to succeed on a global scale with multi-carrier shipping optimization and more.