What we typed
Fender Stratocaster electric guitar in hard shell case
Brand and model are what make an estimate tight. A one-word description falls back to a category average; a specific model gets a specific box.
Marketplace sellers
Mercari shipping label: when you ship on your own
Straight answer first: for an ordinary parcel, use Mercari's prepaid label. It is fixed-rate, it sits below counter pricing, and the tracking lands on the order by itself. This page is about the cases it does not cover — Mercari documents a shipping weight up to 50 lb and a maximum length of 34 in with the second longest side no more than 20 in. Past any of those, Mercari hands the shipment back to you and the cost with it. The length rule catches far more listings than sellers expect.
Live parcel ratesNo signup to buy a labelTracking included
Priced, not guessed
The example on this page is a live quote: 45 × 18 × 7 in at 24 lb, UPS Ground $65.52 on the route below.
A real quote: electric guitar in a hard shell case
On 2026-07-26 we typed “Fender Stratocaster electric guitar in hard shell case” into the SMKlog calculator and asked for Atlanta, GA 30301 to Seattle, WA 98101. A guitar case is the classic Mercari listing that fails the 34-inch length rule while sitting under half the weight limit. Everything below is what came back — no scale, no tape measure, no edited numbers.
Packed box it returned
45 × 18 × 7 in
115 × 45 × 18 cm
Packed weight 24 lb (11 kg).
Route
Atlanta, GA 30301
to Seattle, WA 98101
Both ZIPs are real and priced live — distance and zone move this price more than anything else on the page.
Forty-five inches on the longest side against a 34-inch ceiling. The parcel is 24 lb — comfortably under the 50 lb weight limit — and its second longest side, 18 in, is inside the 20 in rule. One failed check is enough, and it is the length that fails. Length, not weight, is what pushes most Mercari listings onto a seller-bought label.
| Carrier | Service | Price | Estimated transit |
|---|---|---|---|
| UPS | Ground | $65.52 | 7 business days |
| FedEx | Ground Economy | $70.30 | 8 business days |
| UPS | Ground Saver | $87.66 | 6 business days |
| FedEx | Ground | $94.72 | 7 business days |
| UPS | 3 Day Select | $110.64 | 3 business days |
Prices are what you pay at checkout — label plus SMKlog's charge, nothing added later. The cheapest option on this run was UPS Ground at $65.52. Do not read the service names as a price ladder: Ground Saver came in $22 above Ground on this lane and arrived a day sooner. Carriers reprice constantly and every route is different, so treat this as a worked example, not a price list: run your own ZIP codes for today's number.
The three limits
Mercari documents a shipping weight up to 50 lb, a maximum length of 34 in, and a second longest side not exceeding 20 in. Break any one and you ship on your own and carry the cost. Note that the size rule constrains two dimensions, not just the longest one — a short but fat box can fail it.
What usually breaks first
Length. Guitars and cases, floor lamps, curtain rods, skis, long power tools, table legs, fishing rods and golf bags all clear 34 in while weighing a fraction of the limit. Sellers plan around the scale and get caught by the tape measure.
Use the prepaid label when you can
We are not going to pretend otherwise: for a t-shirt, a pair of sneakers, or a boxed game, Mercari's own label is the cheaper and simpler route and the tracking posts itself. Buy your own when the parcel is outside their limits, when a fixed tier prices well above your actual box, or when the buyer found you off the platform.
How to check a listing against the limits in one minute
Measure the packed box, not the item. Three numbers decide whether a prepaid label is even on the table.
| Check | Limit | How to measure it |
|---|---|---|
| Shipping weight | 50 lb | The finished, taped box on a scale — item, padding, and carton together. |
| Longest side | 34 in | The single longest edge of the box. This is the one that catches guitar cases, lamps, and long tools. |
| Second longest side | 20 in | The middle measurement of the three. Easy to miss, and it is what rules out wide flat boxes that pass the length check. |
The guitar case above measures 45 × 18 × 7 in at 24 lb. Longest side 45 in — over the 34 in limit. Second longest side 18 in — inside the 20 in limit. Weight 24 lb — half the 50 lb limit. One failed check out of three is enough: that parcel ships on the seller's own label.
Mercari shipping: common questions
When do I have to ship on my own?
When the parcel is over 50 lb, over 34 in on the longest side, or over 20 in on the second longest side. Also for local delivery and for any sale that happened off the platform. In those cases Mercari does not issue a label and the cost is yours.
Is Mercari's label or my own cheaper?
Theirs, for ordinary small parcels — that is what fixed-rate pricing is for. Yours, when the box is outside their limits, when a fixed tier prices well above your real parcel, or when the sale was not on Mercari.
What are the exact size limits?
Up to 50 lb shipping weight, a maximum length of 34 in, and a second longest side no greater than 20 in. Break one of the three and the prepaid label is off the table.
What does an oversized item actually cost?
The box and the distance decide, not the item. The guitar case above cost $65.52 with UPS Ground coast to coast; the same case on a two-state lane prices far below that. Quote before you promise a shipping figure.
Do I still get tracking?
Yes. Every carrier label carries a tracking number and Mercari lets you enter it manually against the order. Do it as soon as you have the label so the buyer can follow the parcel.
Do I need an account to buy the label?
Not here. Describe the item, enter both ZIP codes, compare live USPS, UPS, and FedEx prices, and pay for the one you pick — no scale and no signup in between.