USPS Ground Advantage Cubic: Tiers, Tracking, Cost
USPS Ground Advantage Cubic prices small parcels by volume, not weight. See the 10 tiers, the 20 lb cap, tracking, insurance and how to measure.
USPS Ground Advantage Cubic is a commercial pricing tier of regular USPS Ground Advantage, not a different product. It prices a parcel by its volume instead of its weight, and it keeps the same USPS Tracking, the same $100 of included insurance and the same 2 to 5 day delivery window. It fits parcels of one cubic foot or less that weigh 20 pounds or less.
What Ground Advantage Cubic is
Ground Advantage Cubic is a price table, not a service. Your parcel travels as USPS Ground Advantage either way. Only the postage formula changes: instead of a price per pound, USPS takes the box's volume and the destination zone and charges one price for the tier the box lands in.
To qualify, a parcel must meet all of these rules from the USPS Domestic Mail Manual, section 283:
- 1 cubic foot or less
- 20 pounds or less
- longest side of 22 inches or less (USPS raised this from 18 inches on July 12, 2026)
- not a roll or a tube
Cubic prices are commercial prices. You will not see them at the Post Office counter. They come through label platforms and other commercial postage channels.
Does USPS Ground Advantage Cubic have tracking?
Yes. A cubic parcel gets the same USPS Tracking and the same $100 of insurance as weight-based Ground Advantage. USPS's Ground Advantage page says tracking is included in the price and that $100 insurance is included on outbound and return shipments. It also lets you buy up to $5,000 of additional coverage for merchandise.
The USPS price list, Notice 123, lists USPS Tracking as included for Ground Advantage Commercial, and the cubic table sits inside that same service. Choosing cubic pricing changes the price, not the tracking or the coverage.
The cubic tiers
USPS defines 10 tiers, from 0.10 to 1.00 cubic foot. A box belongs to the first tier whose limit it does not exceed. The zone 5 column below shows how the price climbs.
| Tier (cubic feet) | Up to (cubic inches) | Zone 5 price |
|---|---|---|
| 0.10 | 172.8 | $9.04 |
| 0.20 | 345.6 | $9.92 |
| 0.30 | 518.4 | $11.51 |
| 0.40 | 691.2 | $13.48 |
| 0.50 | 864 | $14.37 |
| 0.60 | 1,036.8 | $15.15 |
| 0.70 | 1,209.6 | $15.81 |
| 0.80 | 1,382.4 | $16.44 |
| 0.90 | 1,555.2 | $17.06 |
| 1.00 | 1,728 | $18.68 |
Those are USPS's published commercial prices from Notice 123, effective October 4, 2026, not what any seller pays. October 4 is also the day USPS's temporary holiday pricing began, which USPS scheduled to end January 17, 2027, so expect the numbers to move. Our USPS 2026 rate changes post tracks the dates.
The biggest zone 5 steps are 0.30 to 0.40 ($1.97) and 0.90 to 1.00 ($1.62). Soft packs get shorter ladders: poly mailers and padded envelopes are measured by length plus width, up to 36 inches, and only reach tiers 0.10 to 0.50 (length plus width up to 21, 27, 31, 34 and 36 inches). If you are choosing between a mailer and a box, see poly mailer vs box.
How to measure a box for cubic pricing
Pack the box first, then measure.
- Measure length, width and height at the longest point of each side.
- Round each measurement down to the nearest 1/4 inch. USPS's own example: 12-3/8 inches becomes 12-1/4.
- Multiply length by width by height.
- Divide by 1,728 to get cubic feet, then match the result to a tier.
Example: a packed box measures 10-1/8 x 8-3/8 x 5-1/8 inches. Rounded down, that is 10 x 8-1/4 x 5 inches, which multiplies to 412.5 cubic inches. Divided by 1,728, that is 0.239 cubic feet, so the box prices in the 0.30 tier.
Tier edges are sharp. A packed box that works out to 345 cubic inches is in the 0.20 tier. At 346 it is in the 0.30 tier, which is $11.51 against $9.92 at zone 5. Trimming a box by a fraction of an inch can drop it a whole tier.
Dimensional weight works the opposite way. It rounds each side up to the next whole inch and only applies above 1,728 cubic inches. Our dimensional weight guide covers that rule.
Cubic vs weight-based: a worked example
Within a tier and zone, a 2 pound parcel and an 18 pound parcel cost the same. That is why cubic wins for dense boxes and loses for light ones. Here are three boxes, all priced at zone 5 from Notice 123 (effective October 4, 2026):
| Box | Weight | Cubic feet | Cubic tier price | Weight-based price | Cheaper |
|---|---|---|---|---|---|
| 7 x 5 x 4 in | 2 lb | 0.081 | $9.04 (0.10 tier) | $10.50 | Cubic |
| 10 x 8 x 5 in | 6 lb | 0.231 | $11.51 (0.30 tier) | $15.33 | Cubic |
| 12 x 9 x 6 in | 12 oz | 0.375 | $13.48 (0.40 tier) | $8.24 | Weight-based |
One part of this holds in every zone. In Notice 123, a parcel under one pound is cheaper at the weight-based price than at even the smallest cubic tier. Light parcels in roomy boxes belong on weight-based pricing. Small, heavy parcels belong in a cubic tier.
Ground Advantage Cubic vs Priority Mail Cubic
Both are cubic pricing, and both include tracking and $100 of insurance. The differences are speed and price.
| Ground Advantage Cubic | Priority Mail Cubic | |
|---|---|---|
| Delivery window | 2 to 5 business days | 2 to 3 days |
| Delivery guarantee | None | None |
| Tiers in Notice 123 | 10, up to 1.00 cubic foot | 5, up to 0.50 cubic foot |
| Price at the same tier and zone | Lower in every shared cell | Higher in every shared cell |
Example from Notice 123 (effective October 4, 2026): the 0.30 tier at zone 5 is $11.51 on Ground Advantage Cubic and $17.41 on Priority Mail Cubic. Pick Priority Mail Cubic when the buyer paid for speed. Otherwise Ground Advantage Cubic is usually the lower price for the same box. The Priority side is covered in USPS Priority Mail Cubic, explained, and the wider service choice is in Ground Advantage vs Priority Mail.
The July 12, 2026 dimensional change and light boxes
Three Ground Advantage rules changed on July 12, 2026 (the divisor change also covers Priority Mail, Priority Mail Express and Parcel Select):
- Dimensional weight. The divisor went from 166 to 139 for parcels over 1,728 cubic inches. Each side is rounded up to the next whole inch, the volume is divided by 139, and the result is rounded up to whole pounds.
- Cubic size. The longest side limit for cubic parcels rose from 18 to 22 inches.
- Ounce price points. The commercial 4 oz, 8 oz, 12 oz and 15.999 oz rows now carry one price per zone. In Notice 123, a 5 oz parcel and a 15 oz parcel cost the same.
Cubic parcels are one cubic foot or less, so dimensional weight never applies to them. The change bites just past that line. A light 12 x 12 x 13 inch box is 1,872 cubic inches. Divided by 139 and rounded up, it bills as 14 pounds even if it weighs 2. Trim it to 12 x 12 x 12 and it is no longer over the line, so it ships on actual weight and can use the 1.00 cubic tier if it weighs 20 pounds or less.
Getting cubic pricing without a USPS contract
You do not need your own USPS contract. Commercial prices reach small sellers through label platforms, and USPS labels bought through GoatLabels use commercial pricing. GoatLabels quotes USPS, UPS and FedEx on domestic parcels (DHL on international lanes) side by side, with labels paid from a prepaid wallet. There is no monthly fee on Free (up to 50 shipments a month).
Enter the packed dimensions and weight for each parcel and compare the options on one screen.
FAQ
What is USPS Ground Advantage Cubic?
It is a commercial pricing option for USPS Ground Advantage that charges by package volume and zone instead of weight. It is the same service, limited to parcels of 1 cubic foot or less and 20 pounds or less.
Does USPS Ground Advantage Cubic have tracking?
Yes. Cubic is a price table inside Ground Advantage, so it carries the same USPS Tracking as weight-based Ground Advantage.
Does Ground Advantage Cubic include insurance?
Yes. It carries the same $100 of included insurance as weight-based Ground Advantage, and USPS lets you buy additional coverage up to $5,000.
What is the weight limit for Ground Advantage Cubic?
Cubic parcels must weigh 20 pounds or less, measure 1 cubic foot or less and have a longest side of 22 inches or less. Weight-based Ground Advantage goes up to 70 pounds.
How do you measure a box for Ground Advantage Cubic pricing?
Measure length, width and height at the longest points, round each down to the nearest quarter inch, multiply the three and divide by 1,728. The result in cubic feet sets your tier.
Is Ground Advantage Cubic cheaper than weight-based pricing?
Often for small, dense parcels, and not for light ones. In USPS Notice 123 effective October 4, 2026, a parcel under one pound is cheaper at the weight-based price in every zone.
How is Ground Advantage Cubic different from Priority Mail Cubic?
Priority Mail Cubic is faster, 2 to 3 days against 2 to 5 business days, and costs more in every tier and zone that both USPS tables list. Neither delivery window is guaranteed.
Did the July 2026 USPS change affect Ground Advantage Cubic?
Yes. On July 12, 2026 USPS raised the cubic longest side limit from 18 to 22 inches and set the dimensional weight divisor to 139, which applies only to parcels over 1 cubic foot.