Billing reads the outside
Carriers rate the outer dimensions after packing, bulge included. A carton that measures a clean 12 × 10 × 6 empty can tape up half an inch fatter when overstuffed, and that half inch is billable.
Box catalog
Shipping box sizes, priced box by box
Most parcels travel in one of a handful of stock cartons, so we quoted nine of them on 2026-07-27, each packed to the weight it usually carries. Two routes ran the whole ladder: Newark, NJ 07102 to Atlanta, GA 30303 and Los Angeles, CA 90011 to New York, NY 10001. Every figure below is the complete checkout amount with SMKlog’s charge inside it.
Nine cartons quotedBoth coasts coveredAll-in checkout pricing
A ladder, not a guess
Nine cartons, two lanes, one quote day. Rerun any row with your own ZIPs for the current number.
The box ladder, quoted 2026-07-27
Each row pairs a carton with its usual cargo weight and shows the lowest of the five live services returned per lane. Newark, NJ 07102 to Atlanta, GA 30303 sits on the left; Los Angeles, CA 90011 to New York, NY 10001 on the right.
| Box, outer inches | Packed weight | Newark to Atlanta, best rate | Los Angeles to New York, best rate |
|---|---|---|---|
| 9.8 × 7.9 × 3.9 | 1 lb | $9.91 USPS Ground Advantage | $11.12 USPS Ground Advantage |
| 11.8 × 9.8 × 5.9 | 2 lb | $8.48 USPS Ground Advantage | $11.04 USPS Ground Advantage |
| 11.8 × 9.8 × 5.9 | 3 lb | $8.48 USPS Ground Advantage | $11.04 USPS Ground Advantage |
| 13.8 × 11.8 × 5.9 | 5 lb | $13.65 UPS Ground Saver | $19.25 UPS Ground Saver |
| 15.7 × 11.8 × 9.8 | 10 lb | $17.56 UPS Ground Saver | $25.51 UPS Ground Saver |
| 17.7 × 13.8 × 9.8 | 15 lb | $20.50 UPS Ground Saver | $30.48 UPS Ground Saver |
| 17.7 × 13.8 × 11.8 | 20 lb | $23.00 UPS Ground Saver | $35.06 UPS Ground Saver |
| 19.7 × 15.7 × 11.8 | 30 lb | $31.52 UPS Ground | $51.92 UPS Ground |
| 21.7 × 15.7 × 13.8 | 40 lb | $38.45 UPS Ground | $65.52 UPS Ground |
| 23.6 × 17.7 × 13.8 | 50 lb | $45.01 UPS Ground | $76.04 UPS Ground |
Three patterns hide in that ladder. Under about three pounds, the post office owns the bottom row. From five through twenty pounds, UPS Ground Saver kept winning both lanes. At thirty pounds and up, plain UPS Ground took over every time, and the coast-to-coast lane widened its premium with each step. One oddity deserves a callout: the two-pound carton priced below the one-pound carton from Newark, the kind of tier quirk you only catch by quoting live.
Boxes with their own guides
Getting the size decision right
Bigger is rarely safer
Extra air means extra void fill, extra volume, and on large cartons a dimensional-weight bill. Cushion fragile items properly, then do it in the smallest box the padding allows.
Standardize and stop measuring
Sellers who settle on two or three box footprints only ever weigh a new product once. After that, every quote is a repeat of a package they already know.
Box size questions
What are standard shipping box sizes?
The ladder above covers the common run: from a 9.8 × 7.9 × 3.9 in mailer-class carton up to a 23.6 × 17.7 × 13.8 in mover, with the 11.8 × 9.8 × 5.9 in size doing the most work for online sellers.
Which box was cheapest to ship?
The 11.8 × 9.8 × 5.9 in carton at 2 lb, at $8.48 from Newark to Atlanta with USPS Ground Advantage on 2026-07-27. Small and light wins, though the exact winner shifts with the lane.
When does box size beat weight in pricing?
Once a carton passes about a cubic foot, carriers compare its volume against the scale and bill whichever weight comes out larger. Below that size, weight and distance set the price and the box barely matters.
Do I need to buy new boxes?
No. A sound reused carton ships at the same price as a fresh one; the label cares about size, weight and route, not the cardboard’s history. Hide any old barcodes before it goes out.