Is USPS Ground Advantage the cheapest USPS service?
For almost every box on this page, yes. Priority Mail costs more and buys you a day or two, and both include tracking. Ground Advantage is the sensible default under about 10 lb.
USPS
How much does it cost to ship a package with USPS?
USPS Ground Advantage quoted $8.94 for a 12 × 9 × 6 in 5 lb box from New Jersey to Chicago, and USPS was cheapest on most of the light boxes we ran. All four tables come from a single 2026-07-24 run, and what you see is what checkout collects: the label and SMKlog's charge as one figure.
Live parcel ratesReal quotes, datedTracking included
Where USPS wins and where it stops
Boxes, lanes and services below are exactly as they came back on 2026-07-24. Price your own carton before you buy a label.
USPS prices on real boxes
| Box and weight | Cheapest USPS | Estimated transit | Other services quoted |
|---|---|---|---|
| 9 × 6 × 4 in, 1 lb | $11.05 Ground Advantage | 3-4 business days | Priority $14.49 |
| 12 × 9 × 6 in, 5 lb | $8.94 Ground Advantage | 3-4 business days | — |
| 16 × 12 × 10 in, 10 lb | $20.86 Ground Advantage | 3-4 business days | — |
| 18 × 14 × 12 in, 20 lb | $33.44 Ground Advantage | 3-4 business days | — |
| 24 × 18 × 18 in, 50 lb | no rate returned | — | — |
Coast to coast
| Box and weight | Cheapest USPS | Estimated transit | Other services quoted |
|---|---|---|---|
| 9 × 6 × 4 in, 1 lb | $13.00 Ground Advantage | 4-5 business days | Priority $16.47 |
| 12 × 9 × 6 in, 5 lb | $14.16 Ground Advantage | 4-5 business days | — |
| 16 × 12 × 10 in, 10 lb | $30.09 Ground Advantage | 4-5 business days | — |
| 18 × 14 × 12 in, 20 lb | $55.71 Ground Advantage | 4-5 business days | — |
| 24 × 18 × 18 in, 50 lb | no rate returned | — | — |
Small parcels
| Box and weight | Cheapest USPS | Estimated transit | Other services quoted |
|---|---|---|---|
| 6 × 4 × 2 in, 8 oz | $8.88 Ground Advantage | 3-4 business days | Priority $14.49 |
| 9 × 6 × 3 in, 1 lb | $10.89 Ground Advantage | 3-4 business days | Priority $14.49 |
| 10 × 8 × 4 in, 2 lb | $11.12 Ground Advantage | 3-4 business days | Priority $14.71 |
| 12 × 9 × 4 in, 3 lb | $8.88 Ground Advantage | 3-4 business days | Priority $17.66 |
Large parcels
| Box and weight | Cheapest USPS | Estimated transit | Other services quoted |
|---|---|---|---|
| 24 × 18 × 18 in, 30 lb | no rate returned | — | — |
| 30 × 20 × 20 in, 40 lb | no rate returned | — | — |
| 36 × 24 × 18 in, 50 lb | no rate returned | — | — |
| 48 × 24 × 12 in, 35 lb | no rate returned | — | — |
Where USPS returned nothing
Not every carton gets a rate from every carrier. On this run USPS returned no price for 24 × 18 × 18 in, 50 lb to Chicago, 24 × 18 × 18 in, 50 lb to Los Angeles, 24 × 18 × 18 in, 30 lb to Chicago, 30 × 20 × 20 in, 40 lb to Chicago. That is the carrier declining the box, not a gap in the data — the calculator simply shows you whoever did quote.
Common questions
When does USPS stop being the cheapest?
Around 20 lb and above in our run. At 20 lb USPS quoted $33.44 to Chicago while UPS Ground Saver quoted $23.00, and on the 24 × 18 × 18 in 50 lb carton USPS returned no rate at all.
Does USPS charge by size or by weight?
Both. Above one cubic foot the box volume takes over from the scale reading: take the three sides in inches, multiply them out and divide by 139. USPS cut that divisor from 166 to 139 on 12 July 2026, which lifts the billable weight on a large carton by roughly 16 percent. Oversize surcharges begin past 108 inches of length plus girth.
Are these USPS retail prices?
No. These are commercial rates bought online, which sit below the retail counter price. What the quote says is what you hand over: label and SMKlog's charge, nothing behind it.
Can I drop a USPS label at any post office?
Yes, or hand it to your regular carrier, or schedule a free pickup on usps.com. Nothing about the label changes depending on how it enters the network.