Ten box sizes fed through production on 2026-07-27; the USPS rows landed here untouched.
The USPS rows our calculator returned, 2026-07-27
We quoted one carton at ten weights on each coast and kept only the USPS lines. A dash means USPS didn't crack the strongest five options at that weight, which on these lanes starts happening once boxes get heavy. If you came for an explanation of USPS pricing rather than a tool to run it with, our companion article on what USPS charges to ship a package walks the same data with commentary.
Newark, NJ 07102 to Atlanta, GA 30303
| Packed weight | Ground Advantage | Window | Priority Mail | Window |
|---|---|---|---|---|
| 1 lb | $9.91 | 6-7 business days | $14.49 | 4-5 business days |
| 2 lb | $8.48 | 6-7 business days | – | – |
| 3 lb | $8.48 | 6-7 business days | – | – |
| 5 lb | $14.67 | 6-7 business days | – | – |
| 10 lb | $20.86 | 6-7 business days | – | – |
| 15 lb | $23.69 | 6-7 business days | – | – |
| 20-50 lb | – | – | – | – |
Los Angeles, CA 90011 to New York, NY 10001
| Packed weight | Ground Advantage | Window | Priority Mail | Window |
|---|---|---|---|---|
| 1 lb | $11.12 | 6-7 business days | $16.47 | 2-3 business days |
| 2 lb | $11.04 | 6-7 business days | $22.34 | 2-3 business days |
| 3 lb | $11.04 | 6-7 business days | $22.34 | 2-3 business days |
| 5 lb | $20.84 | 6-7 business days | $32.26 | 2-3 business days |
| 10 lb | $30.09 | 6-7 business days | – | – |
| 15 lb | $35.33 | 6-7 business days | – | – |
| 20 lb | $55.71 | 6-7 business days | – | – |
Two things jump out of the raw rows. Identical prices at 2 and 3 lb on both coasts show USPS billing in bands rather than per ounce at this size. And the cross-country Priority Mail lines pair a 2-3 day window with a price that climbs fast, which is the whole USPS trade in miniature: Ground Advantage for patience, Priority for the calendar.
Estimate versus bookable
usps.com lists Ground Advantage from $7.90 and Priority Mail from $11.00 at a Post Office (checked 2026-07-27), and those anchors are honest as far as they go. A starting price just isn't your price. The calculator's rows already contain the ZIP pair, the packed box and SMKlog's charge, so the number survives contact with checkout.
Flat rate deserves a side glance
Per USPS Notice 123 (retrieved 2026-07-27), a Priority Mail flat rate envelope runs $12.90 retail, a medium box $24.80 and a large $34.00. Dense little shipments sometimes beat our quoted rows with those, so compare before committing either way.
Where USPS bows out
From 20 lb up on the Newark lane, no USPS line survived into the strongest five; UPS and FedEx ground tiers owned the heavy boxes. Seeing the absence is useful in itself, and it's the kind of gap a single-carrier tool never shows you.
USPS calculator questions
Which USPS services does the calculator quote?
Ground Advantage showed up on nearly every lane we captured, Priority Mail on many, and Priority Mail Express where it earned a slot; the only Express rows in our 2026-07-27 data were Puerto Rico lanes, at $103.46 from Newark. Media Mail never appeared, since eligibility depends on contents we can't see.
Why do these figures differ from the counter?
A Post Office counter quotes retail off its own scale, and usps.com lists Ground Advantage starting at $7.90 retail (checked 2026-07-27). Our rows are the checkout total for one defined packed box on one ZIP pair, carrier label and SMKlog's charge together, with nothing bolted on later.
Do I need a scale to get a USPS quote here?
No. Type what the item is and the calculator estimates the packed box for you, then shows live USPS rows against UPS and FedEx. Confirm the dimensions look sane before buying, because the label is priced on the box you approve.
How current are the numbers on this page?
Every table row was captured on 2026-07-27 on the two routes named above it. Carriers refile rates often enough that a dated table is a reference point, not a promise, so run the lane fresh when you're ready to ship.