Don't plan a route around USPS
Two boxes, two sizes, ten total rates, zero from USPS. Build a tire shipment around UPS and FedEx and treat a USPS option as a pleasant surprise if the calculator ever returns one, not as the default plan.
Auto parts
Does USPS actually ship tires, or just not say no?
USPS's own restrictions page never mentions tires, so the honest answer looks like yes. Then we ran two ordinary tire boxes through the SMKlog calculator on 2026-08-22, well inside USPS's published weight and size ceilings, and USPS didn't appear in either result. Both times the only services that came back were UPS and FedEx. The tariff clause that most likely explains it, and what a tire-shaped USPS parcel would cost by USPS's own math if it did quote one, are below.
Live rate check, datedCarrier tariff quotedUPS and FedEx priced
Two boxes, zero USPS rates
Both came back on 2026-08-22, well under USPS's own 70 lb and 130-inch ceilings.
What USPS actually prohibits, in its own words
USPS publishes a shipping restrictions page naming exactly what it will not carry and what it carries only with limits. Read on 2026-08-22, it prohibits air bags, ammunition, explosives, gasoline, liquid mercury and marijuana outright, and restricts a long list running from aerosols and alcohol to lithium batteries, live animals, matches, paint and perfume. Tires and automotive parts are absent from both lists. If the question is narrowly "is a tire on the banned list," the page answers no.
That page points anyone chasing edge cases to USPS Publication 52, Hazardous, Restricted, and Perishable Mail, for the categories it only summarizes. A rubber tire with no fluid, no battery and no hazard classification does not obviously belong in either publication, and nothing we read put it there.
What actually came back for two ordinary tires
A published rule and a live quote are different questions, so we asked the second one directly. Both boxes below sit comfortably inside the 70 lb weight limit and the 130-inch length-plus-girth limit that USPS's own USPS Ground Advantage page states, and neither is a hazardous or oddly heavy load. Both were quoted from Newark, NJ 07102 to Columbus, OH 43215 on 2026-08-22.
| What we typed | Packed box | Length + girth | Services returned | Cheapest |
|---|---|---|---|---|
| Single Goodyear Assurance 225/60R16 tire, no rim | 27 × 27 × 9 in 24 lb packed | 99 in 31 in under the USPS ceiling | UPS Ground, UPS 3 Day Select, FedEx Ground, FedEx Ground Economy, UPS Ground Saver No USPS service | $33.61 UPS Ground |
| Single Michelin Road 6 180/55R17 motorcycle tire, no rim | 25 × 25 × 7 in 15 lb packed | 89 in 41 in under the USPS ceiling | UPS Ground, FedEx Ground Economy, FedEx Ground, UPS 3 Day Select, UPS 2nd Day Air No USPS service | $26.85 UPS Ground |
Five rates came back both times, and every one of the ten was UPS or FedEx. If size or weight were the reason, the second, smaller tire would have been the one exception; it wasn't. That points at the shape rather than the numbers, which the next section explains.
The clause that probably explains it
USPS Notice 123, its own price list, was read on 2026-08-22. Among its nonstandard-characteristics surcharges sits this line:
Parcels that contain any of the following characteristics, add $4.50: a. Cylindrical tubes or rolls. b. A can, or wooden or metal box. c. A parcel containing more than 24 ounces of liquid in glass containers, or 1 gallon or more of liquid in metal or plastic containers. d. Other: parcels prepared under 601.3.0 and 601.4.0 with contents that may cause the parcel to roll or not maintain the integrity of the package during processing.USPS Notice 123, pe.usps.com, read 2026-08-22
A rubber tire in a snug box is close to the plainest case of "contents that may cause the parcel to roll" that exists. USPS's general packaging standard, in Domestic Mail Manual section 601.3.1 and read the same day, requires mail to be packaged so contents "do not shift within the mailing container" and to withstand transit "without breakage or deterioration of content." Neither passage names tires, and we are not claiming USPS refuses them as policy. What we can say is that the $4.50 surcharge exists for exactly this shape of problem, and that the live quotes above came back with no USPS option for a box built around a circle.
What USPS's own math would have billed
The formula is not in the price list; it sits in the Domestic Mail Manual, at 133.1.4.3 for USPS Ground Advantage — Retail, read 2026-08-22. Every step below carries the [7-12-26] change mark, meaning this is the version that took effect with the July 2026 prices:
Measure the length, width, and height in inches at their extreme dimensions. Round up each measurement to the nearest whole inch. Multiply the length by the width and then that total by the height. Multiply the result by an adjustment factor of 0.785. If the final result exceeds 1,728 cubic inches, divide the result by 139 and round up to the next whole number to determine the dimensional weight in pounds.USPS Domestic Mail Manual 133.1.4.3, pe.usps.com, read 2026-08-22, marked effective 7-12-26
| Box | Actual weight | Nonrectangular DIM weight | Billed weight if USPS quoted it |
|---|---|---|---|
| 27 × 27 × 9 in | 24 lb | 6,561 in³ × 0.785 ÷ 139 = 37.05 | 38 lb |
| 25 × 25 × 7 in | 15 lb | 4,375 in³ × 0.785 ÷ 139 = 24.71 | 25 lb |
The 0.785 factor exists because a round shape does not fill the box it sits in, so USPS's own rule is gentler to a tire than treating the carton as a solid rectangle would be: the same 27 x 27 x 9 box comes to 48 lb under a plain rectangular calculation and 38 lb under the nonrectangular one. Gentler is not the same as cheap. Both boxes still land well above their scale weight, on top of a $4.50 nonstandard charge, on a service that never returned a rate for either of them.
UPS and FedEx both publish a no-box method
Tape a band around the tire, stick the label to the tread, and expect an additional handling charge on either carrier. That method, and live rates for it, are on the tire shipping guide.
A set of four changes the math entirely
One tire is a parcel question. Four together usually cross into freight territory well before any single-tire carrier choice matters.
Where these rules come from
- USPS, Shipping Restrictions & HAZMAT — the prohibited and restricted item categories; tires and automotive parts are not named. Read 2026-08-22.
- USPS, USPS Ground Advantage — the 70 lb maximum weight and 130-inch maximum length plus girth. Read 2026-08-22.
- USPS, Notice 123, Price List — the $4.50 nonstandard-characteristics surcharge for parcels that may roll or not hold their shape in processing. Read 2026-08-22.
- USPS, Domestic Mail Manual 133.1.4.3 — the nonrectangular dimensional weight formula for USPS Ground Advantage, 0.785 factor and 139 divisor, marked effective 7-12-26. Read 2026-08-22.
- USPS, Domestic Mail Manual §601.3.1 — the general packaging standard that contents must not shift within the mailing container. Read 2026-08-22.
USPS revises its own tariffs and price list without notice, and a live quote can change lane by lane and day by day. Treat this page as what was published and what quoted on the date shown, and re-check before you rely on either.
Shipping a tire through USPS: common questions
Can you ship a tire through USPS?
Nothing on USPS's own restrictions page names tires as prohibited or restricted. But that is not the same as USPS actually quoting one: two live SMKlog checks on 2026-08-22, for a passenger tire and a smaller motorcycle tire, each returned five parcel rates and every single one was UPS or FedEx. Neither box came back with a USPS option.
Why didn't USPS show up in the quote?
USPS's own price list, Notice 123, adds a $4.50 nonstandard charge to parcels whose contents may cause the parcel to roll or not maintain the integrity of the package during processing, the same clause that catches cylindrical tubes and rolls. A loose tire is the plainest possible example of that description, which lines up with what the live quotes showed even though the restrictions page never names tires by name.
What weight and size limit would apply if USPS did carry it?
USPS states a maximum weight of 70 lbs and a maximum combined length and girth of 130 inches for USPS Ground Advantage, on its own Ground Advantage page. Both tire boxes tested here sit well inside those numbers, at 99 and 89 inches of length plus girth, which is what makes the missing USPS rate worth noticing rather than assuming.
How would USPS figure a tire's dimensional weight?
The Domestic Mail Manual gives a separate formula for a nonrectangular parcel at 133.1.4.3: multiply length by width by height, multiply that by an adjustment factor of 0.785, and divide by 139 once the result passes 1,728 cubic inches, rounding up to the next pound. For the 27x27x9 in box quoted here that comes to 38 lb against 24 lb actual; for the 25x25x7 in box it comes to 25 lb against 15 lb actual.
So what's the actual way to ship a tire?
UPS and FedEx, taped and labeled without a box or boxed if you prefer to protect it, both of which SMKlog quotes live. The no-box method both carriers publish, and rates for it, are on the tire shipping guide rather than repeated here.