Dimensional Weight Chart by Box Size (Divisor 139)

Updated August 22, 2026Divisor 13960 stocked sizes

One table of DIM weight for the shipping box sizes people actually use, at the 139 divisor UPS, FedEx and USPS all use since July 12, 2026. Cubic inches, cubic feet, length plus girth and the USPS one cubic foot flag are on the same row so you can size a box and price it in one pass.

How dimensional weight is calculated in 2026

Dimensional weight (DIM weight) is a billable weight the carrier derives from the outside dimensions of the box instead of the scale weight. The formula is length times width times height in inches, divided by a divisor, rounded up to the next whole pound. You are billed on whichever is greater, the actual weight or the DIM weight.

As of July 12, 2026, all three national carriers use the same divisor for domestic parcels: 139. UPS and FedEx have used 139 on daily rates since 2017. USPS moved from 166 to 139 on July 12, 2026, which raised the billable weight of affected USPS parcels by about 19 percent. USPS still applies DIM weight only to parcels larger than one cubic foot (1,728 cubic inches); UPS and FedEx apply it to every package. All three carriers now round each dimension up to the next whole inch before the math, so a 12.2 inch side is billed as 13 inches.

Worked formula: measure the outside of the packed box, round each side up to a whole inch, multiply, divide by 139, round up. Example: 12.2 x 10 x 7.5 in becomes 13 x 10 x 8 = 1,040 cubic inches, divided by 139 = 7.48, billed as 8 lb.

DIM weight chart for common box sizes

The table covers the stocked sizes on this site. Sizes are inside dimensions of the box, which is how corrugated boxes are sold. Outside dimensions run roughly 3/16 to 1/4 inch larger per side for single wall board, so a 12 x 12 x 12 inside box measures about 12.25 x 12.25 x 12.25 outside and the carrier rounds that to 13 x 13 x 13. Use the chart as the floor and expect one size up when the carrier scans a box that sits on a half inch. The USPS column flags boxes over one cubic foot, the threshold where USPS begins applying DIM weight.

Box size (in) Cubic inches Cubic feet DIM lb @139 Length + girth (in) USPS DIM applies
4 x 4 x 4 64 0.04 1 20 No
5 x 5 x 5 125 0.07 1 25 No
6 x 4 x 4 96 0.06 1 22 No
6 x 6 x 4 144 0.08 2 26 No
6 x 6 x 6 216 0.12 2 30 No
7 x 7 x 7 343 0.20 3 35 No
8 x 6 x 4 192 0.11 2 28 No
8 x 8 x 4 256 0.15 2 32 No
8 x 8 x 6 384 0.22 3 36 No
8 x 8 x 8 512 0.30 4 40 No
9 x 6 x 4 216 0.12 2 29 No
9 x 9 x 9 729 0.42 6 45 No
10 x 6 x 4 240 0.14 2 30 No
10 x 8 x 6 480 0.28 4 38 No
10 x 10 x 6 600 0.35 5 42 No
10 x 10 x 8 800 0.46 6 46 No
10 x 10 x 10 1,000 0.58 8 50 No
11 x 8 x 6 528 0.31 4 39 No
12 x 6 x 6 432 0.25 4 36 No
12 x 8 x 6 576 0.33 5 40 No
12 x 9 x 6 648 0.38 5 42 No
12 x 9 x 9 972 0.56 7 48 No
12 x 10 x 6 720 0.42 6 44 No
12 x 10 x 8 960 0.56 7 48 No
12 x 12 x 4 576 0.33 5 44 No
12 x 12 x 6 864 0.50 7 48 No
12 x 12 x 8 1,152 0.67 9 52 No
12 x 12 x 10 1,440 0.83 11 56 No
12 x 12 x 12 1,728 1.00 13 60 No
13 x 13 x 13 2,197 1.27 16 65 Yes
14 x 10 x 8 1,120 0.65 9 50 No
14 x 10 x 10 1,400 0.81 11 54 No
14 x 12 x 10 1,680 0.97 13 58 No
14 x 14 x 8 1,568 0.91 12 58 No
14 x 14 x 14 2,744 1.59 20 70 Yes
15 x 12 x 10 1,800 1.04 13 59 Yes
16 x 10 x 6 960 0.56 7 48 No
16 x 12 x 6 1,152 0.67 9 52 No
16 x 12 x 8 1,536 0.89 12 56 No
16 x 12 x 12 2,304 1.33 17 64 Yes
16 x 16 x 8 2,048 1.19 15 64 Yes
16 x 16 x 16 4,096 2.37 30 80 Yes
18 x 12 x 6 1,296 0.75 10 54 No
18 x 12 x 12 2,592 1.50 19 66 Yes
18 x 14 x 12 3,024 1.75 22 70 Yes
18 x 18 x 12 3,888 2.25 28 78 Yes
18 x 18 x 18 5,832 3.38 42 90 Yes
20 x 14 x 10 2,800 1.62 21 68 Yes
20 x 16 x 12 3,840 2.22 28 76 Yes
20 x 20 x 12 4,800 2.78 35 84 Yes
20 x 20 x 20 8,000 4.63 58 100 Yes
22 x 22 x 22 10,648 6.16 77 110 Yes
24 x 12 x 12 3,456 2.00 25 72 Yes
24 x 18 x 12 5,184 3.00 38 84 Yes
24 x 18 x 18 7,776 4.50 56 96 Yes
24 x 24 x 12 6,912 4.00 50 96 Yes
24 x 24 x 18 10,368 6.00 75 108 Yes
24 x 24 x 24 13,824 8.00 100 120 Yes
26 x 20 x 14 7,280 4.21 53 94 Yes
30 x 20 x 20 12,000 6.94 87 110 Yes
36 x 24 x 24 20,736 12.00 150 132 Yes

Worked examples: actual vs dimensional

DIM weight bites hardest on light, bulky goods: pillows, apparel, foam, empty containers. It rarely matters for dense goods like books, hardware, canned food or liquids, where the scale weight is already higher than the DIM figure.

Box Actual weight Cubic inches DIM weight @139 Billable weight
12 x 12 x 12 in, 25 T-shirts 9 lb 1,728 13 lb 13 lb (DIM wins)
16 x 12 x 6 in, 6 hardcover books 14 lb 1,152 9 lb 14 lb (actual wins)
18 x 18 x 18 in, throw pillows 6 lb 5,832 42 lb 42 lb (DIM wins by 36 lb)
8 x 6 x 4 in, phone accessories 1 lb 192 2 lb 2 lb (DIM wins by 1 lb)

How to cut DIM charges

  • Drop one size. Going from 14 x 14 x 14 to 12 x 12 x 12 cuts cubic inches from 2,744 to 1,728, and DIM weight from 20 lb to 13 lb. That is the single biggest lever on the chart.
  • Match the depth. A 12 x 12 x 6 box bills at 7 lb, half of the 12 x 12 x 12 figure. Shallow and multi-depth boxes exist for this reason. See the box size chart for the shallow sizes in each footprint.
  • Stay under one cubic foot for USPS. Any box at or below 1,728 cubic inches ships USPS on actual weight only. 12 x 12 x 12 is exactly the line; 12 x 12 x 10 (1,440) sits comfortably under it.
  • Use a mailer for soft goods. A poly mailer or bubble mailer has almost no DIM weight. The mailer vs box guide covers when that is safe.
  • Watch length plus girth. The last column matters for surcharges: UPS and FedEx add a Large Package charge above 130 inches, USPS treats 108 to 130 inches as oversized. Full thresholds are on the carrier size and weight limits page.

Where the divisor still differs

Retail and commercial USPS, UPS daily and UPS Ground, FedEx Express and Ground all sit at 139 for domestic shipments billed in pounds. Shipments billed in kilograms use 5,000 (cubic centimeters per kilogram) at UPS, FedEx and DHL, which is the metric equivalent of 139. Some negotiated contracts still carry a higher divisor such as 166 or 194; if your account has one, the billable weight in the chart falls by roughly 16 to 28 percent. Amazon FBA uses its own tiers rather than a divisor.

Sources: USPS Domestic Mail Manual 133 (dimensional weight, retrieved August 2026), USPS Notice 123 price list effective July 12, 2026, UPS and FedEx published dimensional weight pages (retrieved August 2026).

Shop corrugated boxesShallow and multi-depth boxes

Frequently asked questions

What is the dimensional weight of a 12x12x12 box?

1,728 cubic inches divided by 139 is 12.43, which rounds up to 13 lb. A 12 x 12 x 12 inside-dimension box will usually scan at 13 x 13 x 13 outside, which is 2,197 cubic inches and 16 lb. Keep the scale weight above that and DIM is irrelevant.

Does USPS use dimensional weight?

Yes, for parcels larger than one cubic foot (1,728 cubic inches). Since July 12, 2026 USPS uses the 139 divisor for Priority Mail, Priority Mail Express and USPS Ground Advantage, the same number as UPS and FedEx. Flat rate boxes are exempt because the price is fixed.

Is the dimensional weight divisor 139 or 166?

139 for UPS, FedEx and USPS domestic shipments as of July 2026. 166 was the USPS divisor until July 11, 2026, and it survives only in some negotiated UPS and FedEx contracts.

Do carriers round dimensions up?

Yes. Each side is rounded up to the next whole inch before multiplying, and the final DIM weight is rounded up to the next whole pound. Measure the packed box with the bulge, not the flat box spec.

How do I avoid dimensional weight charges?

Use the smallest box the contents allow, prefer a shallow depth over a cube, keep USPS parcels at or under 1,728 cubic inches, and ship soft goods in mailers. Each step down in box size reduces DIM weight faster than it reduces material cost.

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