Straight answers on shipping costs, carrier comparisons, and the math carriers use to price your packages.
Shipping cost comes from three inputs: billable weight (actual or dimensional, whichever is larger), the shipping zone between origin and destination, and the carrier's base rate. The formula and a worked example are here.
Read →USPS tends to win on lightweight packages and flat-rate options. UPS and FedEx are often cheaper for heavier packages shipping across many zones. Here is how to put all three side by side.
Read →Dimensional weight (DIM weight) is a calculated weight based on package volume. If it exceeds actual weight, carriers charge for it instead, and USPS's own divisor is changing July 12, 2026.
Read →The main levers: right-sizing your packaging, using flat-rate options for dense items, matching service level to actual delivery need, and comparing all three carriers before printing every label.
Read →Shipping zones are distance tiers numbered 1 to 8 (or 1 to 9 for some services) from origin to destination ZIP. A higher zone number means a longer trip and a higher rate for the same package.
Read →Flat rate charges a fixed price regardless of weight or distance, which sounds appealing until the package is light. For small, light packages at nearby zones, weight-based pricing usually wins.
Read →ShipCompare's own modeled USPS, UPS and FedEx ground price tiers by weight and zone, with methodology, sources and a downloadable CSV.
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