FedEx and UPS Dimensional Weight Rounding: How a New Rounding Policy Can Inflate Shipping Costs 231%

On August 18, FedEx and UPS quietly changed the way they measure packages, and the result is a wave of unplanned cost increases that most shippers won’t notice until the invoices start rolling in.

It might sound like a minor technical tweak, but the reality is this: Carriers now round every package dimension up to the next whole inch.

How carriers changed their dimensional weight rounding policies

Previously, carriers rounded each dimension to the nearest inch, up or down. Now, every fractional inch rounds up. That means nearly every box in your network just got “bigger” on paper, and your billable weights likely just got heavier.

Let’s say your box measures 10 x 10.1 x 10.3 inches.

Before August 18, that package rounded to 10 x 10 x 10 inches.

Now, it rounds to 10 x 11 x 11 inches.

That’s a 4.3% increase in dimensional size, and a higher transportation cost, even though your product didn’t change at all.

For high-volume shippers, those fractions compound fast. And for boxes near critical thresholds, especially 5 cubic feet (8,640 cubic inches) – the impact is even greater.

The 5 Cubic Foot Trap: When Rounding Pushes You Over the Line

Packages that measure under 5 cubic feet typically benefit from your negotiated DIM divisor, keeping billable weights reasonable. But once a shipment crosses that 8,640 cubic inch threshold, the rules change dramatically:

• Your custom DIM factor no longer applies.
• The package is hit with Additional Handling (AH) fees.
• The billed weight jumps – sometimes doubling or tripling instantly.

Real example: A 231% cost increase

Let’s take a look at the same box dimensions, but with the old and new rules applied.

Before August 18

• Box: 20 x 20 x 20 inches = 8,000 cubic inches (under 5 cu. ft.)
• Billed Weight: 20 lbs
• Total Cost: $17.23

After August 18 (with rounding)

• Box: 20 x 20.1 x 20.3 → rounds to 20 x 21 x 21 = 8,820 cubic inches
• Billed Weight: 40 lbs
• Additional Handling Fee: $36
• Total Cost: $57.18

Same box. Same shipment. +231% cost.

The product didn’t change. The packaging didn’t change. The only thing that changed was the rounding rule.

Most shippers won’t see the additional cost coming

This rule change didn’t make headlines. Most invoices don’t show decimals.

And many warehouse systems already round dimensions before transmitting them to the carrier.

Even carrier account managers were caught off guard. That means even sophisticated shippers could be absorbing the cost impact without realizing why their billed weights and AH fees are climbing.

How to know if you’re affected

You don’t need new software to spot the signs, just smarter tracking. Start here:

• Average Cost per Parcel: Look for a noticeable bump after August 18.
• Build vs. Actual Weight Gap: If your billed weight jumped 1-2 lbs on average, rounding is likely to blame.
• Additional Handling Incidence: Track whether AH fees are appearing more often.

If you’re seeing any of these shifts, you’re likely paying for airspace your product never occupied.

How to protect your margins

You can’t rewrite carrier policy, but you can adapt strategically. Here’s our advice:

• Audit your carton library. Identify SKUs using boxes near the 8,000-8,640 cubic inch range. These are your highest risk for crossing thresholds.
• Run a DIM Impact Model. Compare pre- and post-August billing data by box size, service type, and zone to uncover rounding-related cost spikes.
• Reevaluate packaging. A one-inch trim in width or height can restore your DIM divisor and avoid AH fees entirely.
• Quantify your exposure. Use invoice data to calculate the monthly cost of these “invisible inches.”
• Explore network alternatives. Run multi-carrier models to see if regional or alternative networks offer relief.

Use this opportunity to reevaluate your packaging and revisit your shipping strategy

While every shipper is feeling the ripple effects of this policy, few are actively modeling its impact. That’s where opportunity lies.

By tightening measurement accuracy, auditing packaging, and tracking dimensional trends, you can reduce unnecessary fees and, in many cases, recover lost margin.

The August 18 rounding change may look small on paper, but it signals a much bigger shift in how carriers capture revenue. Instead of headline rate hikes, carriers are using policy mechanics – like rounding and dimensional thresholds – to quietly reshape parcel costs behind the scenes.

Visibility into your dimensional data is now a critical part of cost control.

By understanding how rounding rules and thresholds work, shippers can make informed packaging, measurement, and contract decisions, protecting margins before the costs ever appear on the bill.