Priority Mail days, by route
USPS publishes a service standard for every pair of ZIP-code areas. Across the contiguous US they spread like this:
| USPS standard | Share of routes |
|---|---|
| 2 days | 3.2% |
| 2–3 days | 15% |
| 3 days | 82% |
Share of the 814,000 pairs of three-digit ZIP areas in the contiguous US, from USPS's Priority Mail service standards effective November 1, 2026. A range means some ZIP codes in the pair take the longer number.
Two things stand out. Distance matters less than you'd expect: most of the country is 3 days from most of the rest, whether it's 500 miles or 2,500. And no route between ZIP-code areas is officially 1 day; even local Priority Mail is 2.
Sample routes
Routes between big cities often beat the overall mix above:
| Route | Miles | USPS standard (days) |
|---|---|---|
| New York → Los Angeles | 2,460 | 2–3 |
| Chicago → Houston | 940 | 3 |
| Atlanta → Miami | 610 | 3 |
| Boston → Washington, DC | 390 | 2 |
| Denver → Dallas | 660 | 3 |
| Seattle → Portland, OR | 140 | 2–3 |
| Phoenix → Las Vegas | 250 | 2 |
| Minneapolis → St. Louis | 470 | 2 |
What counts as a day
USPS counts Monday through Saturday and skips Sundays and its holidays. The day it accepts the package is day 0. So a 2-day Priority Mail package mailed Thursday is due Saturday, and one mailed Friday is due Monday. Work out the exact date.
Is it guaranteed?
No. Priority Mail days are USPS's expected delivery, not a promise, and there's no refund if it's late. If you need a guarantee, Priority Mail Express has a money-back guarantee on most routes. For price, see USPS postage cost; Flat Rate boxes are often cheapest for heavy items going far.
USPS's own numbers
Days are counted from the day the carrier accepts the package (day 0), skipping Sundays and holidays. Holiday peak (mid-November to late December) can add a day or more. For a specific shipment, check the carrier's own tool.
Service information checked November 2026.
Other services
- USPS First-Class MailLetters, cards and large envelopes.
- USPS Ground AdvantageUSPS's everyday package service.
- USPS Priority MailFaster USPS packages, with Flat Rate boxes.
- USPS Priority Mail ExpressUSPS's fastest service, with a money-back guarantee.
- UPS GroundUPS's economy service, zip to zip.
- FedEx Ground and Home DeliveryFedEx's economy services, zip to zip.
Or compare every carrier at once on the delivery-time calculator.
Questions people ask
Is Priority Mail 2 or 3 days?
It depends on the route: 3% of routes in the contiguous US are 2 days and most of the rest are 3, under USPS's own standards. Enter both ZIP codes above to see yours.
Does Priority Mail deliver on Saturday?
Yes. USPS delivers Priority Mail on Saturdays and counts Saturday as a delivery day. It doesn't deliver regular Priority Mail on Sundays or holidays.
Is Priority Mail faster than Ground Advantage?
Usually by a day or two on longer routes. Nearby, they're often the same. Compare both for your route on the delivery-time calculator.