The ShipWave Parcel Rate Index

The ShipWave Parcel Rate Index prices one fixed basket of packages — six weights across USPS zones 2–8 — across USPS, UPS, and FedEx on a single day using ShipWave’s live multi-carrier rate engine. The finding: the cheapest carrier flips by weight and zone. UPS Ground Saver tends to win the lightest packages, USPS Ground Advantage wins many mid-weight (~5 lb) parcels, and FedEx Ground wins most heavy parcels (20–50 lb).

Comparing each carrier’s cheapest economy-ground service for the identical box, the best-vs-worst spread averaged 129% across the basket and reached nearly 300% on some heavy-parcel cells. In practical terms: defaulting to one carrier means overpaying on most orders. That is the entire case for multi-carrier rate-shopping. See the full per-cell tables and methodology in the Parcel Rate Index.

Every figure in the index is a live quote returned by ShipWave’s rate engine — not a list price or an estimate — reported as the commercial (discounted) rate before any ShipWave markup. We never fabricate rates. The index is refreshed quarterly so editions stay comparable as general rate increases, surcharges, and rule changes (like the July 12, 2026 USPS dimensional-weight change) move real quoted rates.