USPS Priority Mail Zone Pricing Explained

A 5-pound Priority Mail package costs about $10.50 if it's going across town and nearly $18.75 if it's going coast-to-coast. Same service, same box, same weight — the only difference is distance, and that difference almost doubles the price. If you offer flat-rate shipping to your customers without understanding your zone distribution, you're either overcharging nearby buyers or losing money on distant ones. Probably both.

How Zones Work

USPS divides the country into shipping zones numbered 1 through 9, based on the distance between your origin ZIP code and the destination. Zone 1 covers packages going less than 50 miles — essentially your own city or metro area. Zone 2 extends to about 150 miles, roughly within your state. By zone 5, you're covering 600 to 1,000 miles, which on the East Coast means New York to Atlanta or Chicago. Zone 8 is coast-to-coast, and Zone 9 covers Hawaii, Alaska, and US territories.

The zone is determined by the first three digits of the origin and destination ZIP codes. USPS publishes zone charts that map every 3-digit prefix pair to its corresponding zone. Shipping platforms calculate this automatically, but understanding the concept matters because zone distribution directly determines your average shipping cost.

One quirk worth knowing: zones aren't always symmetric. The zone from point A to point B can occasionally differ from B to A because of how USPS routes packages through its network of regional distribution centers. The difference is rare and usually only one zone, but it exists.

What Zone Pricing Actually Looks Like

Priority Mail Commercial Base pricing in 2026 creates a wide cost range for the same package weight. A 1-pound package runs about $8.10 for zones 1-2 and $12.50 for zone 9. A 3-pound package ranges from $9.25 locally to around $17.90 cross-country. At 5 pounds, you're looking at $10.50 for nearby zones up to $20.75 or so for the farthest destinations.

The rate curve isn't linear, either. The jump from zone 1-2 to zone 3 is small — maybe 50 cents to a dollar. But the jump from zone 6 to zone 7, and especially zone 7 to zone 8, is steep. This means most of your cost variance comes from a relatively small percentage of long-distance shipments. A seller whose orders are 80 percent zones 1-4 and 20 percent zones 7-8 might find that the 20 percent of distant orders account for 35 percent of total shipping spend.

Commercial Base pricing, which you get through any shipping platform, runs about 10 to 15 percent less than retail counter rates. Commercial Plus pricing, available to shippers moving very high volumes, saves another 5 to 8 percent on top of that. If you're still paying retail rates by buying postage at the post office, switching to commercial pricing through a platform like atoship is the single easiest way to reduce your shipping costs.

Why Your Zone Distribution Matters

Your zone distribution — the percentage of orders going to each zone — is probably the most important shipping metric most sellers never look at. It determines your true average shipping cost and tells you whether flat-rate shipping offers make financial sense.

A seller in Kansas City, roughly the geographic center of the continental US, has a natural advantage. Most shipments stay within zones 1 through 5, and zone 8 shipments are rare. Their average zone might be 3.5, keeping costs moderate across the board. A seller in Miami or Seattle, by contrast, has a skewed distribution — half the country is zone 5 or higher, pushing the average zone to 5 or 6 and driving up costs meaningfully.

To calculate your zone distribution, export your last 500 or 1,000 shipments from your platform and look at the zone breakdown. If your average zone is below 4, you're in a strong position for competitive shipping rates. If it's above 5, you need to account for that in your pricing or consider strategies to bring it down.

Strategies to Lower Your Average Zone

The most effective strategy is shipping from multiple locations. If you split inventory between an East Coast and West Coast warehouse, most orders ship from the closer facility, dropping the average zone by 1 to 2 zones. At scale, a single zone reduction across thousands of shipments saves tens of thousands of dollars annually. This isn't practical for small sellers, but becomes worth exploring once you consistently ship more than 1,000 packages monthly.

For single-location sellers, geography is destiny, but you can still optimize. Choose your warehouse location strategically when you have the option — central US locations like Dallas, Memphis, or Indianapolis minimize maximum distance to any customer. If you already have a fixed location, focus on marketing and customer acquisition in nearby zones where your shipping economics are strongest.

Another approach is offering tiered shipping. Charge less for standard shipping (which you fulfill with Parcel Select Ground or Ground Advantage at lower zone-based costs) and more for expedited shipping (Priority Mail). This way, long-distance customers who choose standard shipping cost you less than they would on Priority Mail, while nearby customers who choose expedited still get a good deal.

Flat Rate as a Zone Hedge

USPS Priority Mail Flat Rate boxes exist specifically to eliminate zone pricing uncertainty. A Medium Flat Rate box costs about $14.45 Commercial Base regardless of zone. If your typical shipment would cost more than $14.45 at zone-based pricing — which happens for packages over 3 pounds going to zone 5 or beyond — Flat Rate saves money.

The flip side is that Flat Rate is wasteful for nearby shipments. That same 3-pound package going zone 2 costs only about $9.90 at zone-based pricing, meaning Flat Rate would cost you an extra $4.55 for no benefit. Sellers who blindly use Flat Rate for everything overpay on local shipments to get peace of mind on distant ones.

The optimal strategy is comparing zone-based and Flat Rate pricing for each shipment and choosing the cheaper option. atoship's rate comparison does this automatically, showing you both options side by side so you can pick the best price for every package without manual calculation.