Put two auto parts on a scale and you learn very little about what they cost to send. On 2026-08-07 a 36 lb pair of brake rotors quoted $36.03 to Chicago while a 28 lb bumper cover quoted $294.40 to Denver: the lighter of the two parts, and much the larger of the two figures. The box is doing the work, and two published size thresholds decide when it starts. Nine parts went through our own quote that day. Six came back with rates, one came back with nothing, and two were never going to price at all.
The scale sets the floor. The longest side, the second-longest side and the girth are what actually decide which band a part lands in.
| What we typed | Packed box | Going to | Cheapest quote |
|---|---|---|---|
| Remanufactured alternator for a Honda Accord | 12 × 10 × 9 in 15 lb | Atlanta, GA | $15.21 USPS Ground Advantage, 3 days |
| Pair of gas charged front struts for a Honda Civic | 26 × 10 × 10 in 18 lb | Atlanta, GA | $21.78 FedEx Ground Economy, 5 days |
| Pair of front brake rotors for a Ford F-150 | 14 × 14 × 8 in 36 lb | Chicago, IL | $36.03 UPS Ground, 4 days |
| Radiator for a Chevrolet Silverado, foam corners | 32 × 26 × 6 in 22 lb | Dallas, TX | $38.89 UPS Ground, 5 days |
| Headlight assembly for a Toyota Camry, factory carton | 28 × 18 × 14 in 11 lb | Denver, CO | $60.75 UPS Ground, 5 days |
| Front bumper cover for a Ford F-150, boxed | 66 × 30 × 18 in 28 lb | Denver, CO | $294.40 UPS Ground, 5 days |
| Steel hood panel for a Honda Civic, wooden crate | 60 × 52 × 10 in 62 lb | Chicago, IL | No parcel option returned |
| Driver side airbag module removed from a Toyota Camry | 14 × 12 × 10 in 8 lb | Atlanta, GA | No parcel option returned |
| Used fuel pump removed from a car, still wet with gasoline | 12 × 10 × 8 in 6 lb | Atlanta, GA | No parcel option returned |
The headlight row is the one people argue with. Eleven pounds in a factory carton quoted above thirty-six pounds of iron, and two things push that way at once: Denver is a longer haul than Chicago, and the carton holds 4.1 cubic feet against the rotors' 0.9. Carriers bill the larger of what the scale says and what the box implies, so a hollow part in a big carton pays like a heavy one.
Body and lighting parts are large and light, which is the exact shape carriers charge extra for. Both publish where the lines fall, and neither hides them.
| Measurement | UPS | FedEx |
|---|---|---|
| Longest side | Additional handling over 48 in; large package over 96 in | Oversize over 96 in |
| Second-longest side | Additional handling over 30 in | — |
| Length and girth combined | Large package over 130 in | Oversize over 130 in |
| Box volume | Additional handling over 10,368 cu in; large package over 17,280 cu in | — |
| Weight | Additional handling when the average package in a shipment is over 50 lb; large package over 110 lb | — |
| Billed weight once over | Minimum 90 lb on a large package | Minimum 90 lb on an oversize package |
| Where a package stops being one | 150 lbs, 108 in of length, 165 in of length and girth | Heavier than 150 lbs, or more than 165 in of length and girth |
Run the bumper cover through that grid. Length plus girth on a 66 by 30 by 18 inch box is 66 plus twice 30 plus twice 18, which is 162 inches. That clears the 130 inch line at both carriers, so the box is a large package, and UPS states the consequence plainly: with the exception of UPS Ground with Freight Pricing packages, large packages are subject to a minimum billable weight of 90 pounds. FedEx sets the same 90 lb floor on an oversize package. Twenty-eight pounds of plastic gets billed as ninety, and $294.40 stops being mysterious. The board ran from there up to $952.30 at the top on the same box.
One detail saves money more often than any other. UPS notes that an additional handling charge is not assessed when a large package surcharge is applied, so the two do not stack. What that means in practice is that a panel sitting just under 130 inches of length and girth but over 48 inches on its longest side still picks up additional handling, and shaving the box does not help until it drops under both lines. Measure before you order the carton, not after.
The crated hood is the boundary case, and it answers itself. A 60 by 52 by 10 inch crate measures 60 plus twice 52 plus twice 10, which is 184 inches of length and girth. UPS caps a package at 165 inches of length and girth combined, and FedEx treats a combined length and girth of more than 165 inches as freight rather than as a package. Our quote returned nothing for that crate, which is what the published ceilings predict.
Above that line the part does not become unshippable, it becomes a different product. Hoods, tailgates, doors, bumpers for full-size trucks, engines, transmissions, axle assemblies and anything on a skid go on a pallet and move by LTL, priced by class and dimensions rather than by a parcel rate table. That path runs through freight review, where a person quotes the lane. If you are weighing the two, where parcel stops and LTL starts sets out the crossover, and building a pallet covers what a handling unit has to look like when it arrives.
One warning about crating a marginal part. Whatever the crate measures is what gets rated, not the panel inside it, so a hood that would have measured 168 inches loose can measure 190 in lumber and skip straight past the ceiling. Crate for protection when the part genuinely needs it, and check the outside dimensions before the lid goes on.
Two of the nine came back empty for a different reason than size. UPS publishes a list of common items that may be hazardous, and the automotive entries are short enough to read in full. Read 2026-08-07.
UPS describes the entry as items that “May contain Air Bag Inflators, or Air Bag Modules or Seat-Belt Pretensioner.” Our quote for a driver side module out of a Camry returned no parcel options, and that is the right outcome rather than a bug.
Two entries, nearly the same wording. Auto parts “May include carburetors, gas lines, or gas tanks which may contain gasoline”; engine parts may contain “fuel or fuel residue”. A used pump described as wet with gasoline returned nothing.
The battery entry names “spillable lead-acid batteries, many lithium batteries” among the regulated types. A starting battery out of a car is the spillable kind, and it has its own rules and its own page here.
The contrast in the table is worth noticing. The pair of gas charged struts quoted normally at $21.78, because a new sealed unit is a different article from a used part that has held fuel. What decides which check a part gets is the description you type, so describe it the way it actually is. A used pump entered as a pump gets a different answer than the same pump entered honestly as fuel-wetted, and the second answer is the one that will not strand a package at a hub.
Where a part is genuinely regulated, the route is a hazmat-capable service rather than an ordinary label. Our page on hazmat shipping covers what that involves.
Boxed parts price in about a minute in the calculator. Panels, engines and anything on a skid go through freight review.
Surcharge thresholds and package ceilings are revised by both carriers, usually at the start of a year and sometimes mid-year. The figures above are what those pages published on the date shown. The prices in the first table are live quotes from that same day and are not a rate card; re-quote the part you actually have.
$15.21 to $294.40 for the six parts priced here on 2026-08-07, all leaving Berkeley Heights, NJ. Weight is not what spreads them: the cheapest box held a 15 lb alternator and the dearest held a 28 lb bumper cover.
Anything past the published package ceilings. UPS publishes a maximum package weight of 150 lbs, a maximum length of 108 inches and 165 inches of length and girth combined, and FedEx treats weight heavier than 150 lbs or length and girth over 165 inches as freight. A crated hood at 60 by 52 by 10 inches measures 184 inches of length and girth, and our quote returned no parcel options for it.
It crossed a size line rather than a weight line. At 66 by 30 by 18 inches that box measures 162 inches of length and girth, over the 130 inch large package threshold both carriers publish, and a large package carries a minimum billable weight of 90 pounds whatever the scale reads.
Our quote returned no parcel options for one. UPS lists air bags among common items that may be hazardous, describing them as items that may contain air bag inflators, or air bag modules or a seat-belt pretensioner, which is regulated territory rather than ordinary parcel.
Not on an ordinary quote. UPS names auto parts and engine parts as items that may include carburetors, gas lines or gas tanks which may contain fuel or fuel residue. Our quote for a used fuel pump described as still wet with gasoline returned no parcel options.