UPS will align its dimensional weight (DIM) calculation method with FedEx starting August 18, 2025, rounding all fractional package dimensions—length, width, and height—up to the next whole inch.

Previously, UPS rounded down dimensions less than 0.5 inches. Now, even a package measuring 11.1 inches will be billed as 12 inches, raising its DIM weight and potentially shipping costs.

Industry Impact:

Imtiaz Kermali of eShipper estimates that a merchant shipping 2,500 packages per month could see $32,000+ in extra annual costs from this change alone. This shift comes amid rising carrier rates, global supply chain volatility, and a competitive pre-holiday season.

Impact Analysis for Sellers

  • Shipping cost increases due to higher billed weights, even if the package size hasn’t changed.
  • Tighter margins for high-volume, lightweight-but-bulky items (e.g., apparel, bedding, decor).
  • Potential fulfillment strategy changes as sellers seek to offset rising costs.
  • Pressure to optimize packaging to avoid unnecessary dimensional upcharges.

Recommended Next Steps

  1. Audit Your Packaging
    –>Redesign boxes to fit products more snugly.
    –> Consider poly mailers or padded envelopes for non-fragile items.
  2. Run Cost Simulations
    –> Use carrier-provided DIM weight calculators with the new rounding rule.
    –> Identify SKUs most affected and explore alternative packaging or fulfillment methods.
  3. Evaluate 3PL Options
    –> Partner with fulfillment providers that offer packaging optimization, hybrid shipping, or negotiated carrier rates.
  4. Test Alternative Carriers
    –> Compare regional carriers, USPS, and hybrid services for cost advantages.
  5. Communicate with Customers
    –> Adjust pricing or shipping thresholds to balance profitability and competitiveness before the Q4 rush.

Source: Supply Chain Dive

CedCommerce Take

Whether you ship from Shopify, WooCommerce, Amazon, eBay, or your own warehouse, these shipping costs could eat into your margins fast—especially heading into the holiday season. Sellers should use August as a packaging audit month and diversify carrier strategies.
We recommend pairing cost optimization with multichannel selling, because if you’re only relying on one channel or one fulfillment method, changes like this hit harder. CedCommerce’s multichannel tools can help centralize your order management and keep costs predictable.

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cedcommerce coverage UPS dimension calculation update