Arrival Spread Beats Average Transit: Sorting Lines by Reliability

Convert before you compare

Units disagree before the lines do. Register rates are quoted per kilogram against a chargeable weight that may be volumetric rather than measured; arrival windows are published as ranges in whole days; and catalogue prices in this site’s snapshot are quoted in dollars against yuan figures whose implied rate is not constant. Ranking anything before those three conversions are pinned produces a table that looks precise and decides nothing.

Money first. The snapshot’s 218 rows imply a mean of 6.232 CNY per USD, and that is the figure the currency tool loads by default. Row-level pairs do not all sit on that mean — the six rows sampled in the companion note on rebuilding a table row imply between 6.327 and 6.336 — so a converted figure should carry the rate it used rather than appearing as a bare number.

Weight second. A per-kilogram rate describes a billing rule, not a price: the first kilogram is usually charged at a different band from the rest, and the divisor decides how many kilograms a box is billed for. Days last. A typical figure without its fastest and slowest edges is a midpoint of somebody else’s template, not an observed median.

What this comparison is allowed to claim

Every figure in the table comes from this site’s parameter register, where each entry carries a status of not verified because no live rate could be confirmed at the time of review. The six shapes are therefore described as transport shapes rather than as brands: economy air, battery-friendly air, priority air, postal small parcel, sea–rail and a sensitive goods line.

Three consequences follow. The costs below are arithmetic on those template values, reproducible from the rate and the fixed band. The arrival columns are published bands, not observations of parcels already delivered. And no ranking here is a recommendation; it is a description of what the register implies for one stated parcel weight.

Arrival spread is defined as the slowest published day minus the fastest, and it is the column this note is named after. Spread is silent about the midpoint and loud about the risk: a shape with a 22-day spread can arrive when the midpoint predicts, but it can also arrive three weeks later, and no amount of planning changes which.

Five columns, one table

The comparison below holds one thing constant so the rest can vary. It assumes a United States delivery address, because all six shapes list the United States as served, and it assumes 2 kg of chargeable weight. Cost at 2 kg is the fixed band plus the per-kilogram rate multiplied by two: 18 + 22 for economy air, 20 + 28 for the battery-friendly shape, 24 + 38 for priority air, 10 + 26 for postal air, 26 + 10 for sea–rail and 22 + 32 for the sensitive goods line.

Chargeable weight, not scale weight, is the multiplier, which is why the divisor column sits next to the cost column rather than in a footnote. Two shapes quote a divisor of 5000 and four quote 6000, so the same physical box can be billed at 4.8 kg on one line and 4.0 kg on another. Until that is resolved, a cost column is a projection.

Reading the five columns in order

Cost is read first only because it is the column people arrive with. On the stated parcel, postal air and sea–rail tie at $36.00, economy air follows at $40.00, the battery-friendly shape at $48.00, the sensitive goods line at $54.00 and priority air at $62.00. A 72 percent gap separates the cheapest column entry from the most expensive one, which is a large enough difference that the other columns have to justify it rather than the reverse.

Typical arrival is read second, and it is a midpoint rather than a promise. Fourteen days against seven is a real seven-day difference on paper; whether it survives contact with a queue is a different question. Spread is read third and carries the most information per character, because it describes how much of the plan can slip. Five of the six shapes sit above the 10-day mark this site’s comparison tool uses to flag a line as uncertain, and only priority air falls inside it.

The divisor is read fourth. It changes nothing for a dense 2 kg parcel and a great deal for a light, bulky one, and it is the column most often left out of third-party comparisons. Status is read last but never skipped: a column of template values marked not verified tells you what kind of claim you are holding.

Consistency check: where the columns disagree

Four checks are worth running before the table is believed. The first is arithmetic. Spread equals typical for four of the six shapes, which is an artefact of how the template bands were written rather than an observed property of those routes; the coincidence should be treated as unverified and not read as a pattern.

The second check is ordering. The cheapest column is not the fastest column and the fastest column is the most expensive one, so the table cannot be collapsed into a single score without stating a priority first. The third is the divisor. Take a box measuring 40 × 30 × 20 cm: 24,000 cm³ becomes 4.8 kg at a divisor of 5000 and 4.0 kg at 6000. Priority air then costs 24 + 19 × 4.8 = $115.20 while economy air costs 18 + 11 × 4.0 = $62.00, and the sensitive goods line costs 22 + 16 × 4.8 = $98.80. The headline rate never changed; the volume rule did.

The fourth check is scope. A 2 kg table describes a light parcel and nothing else. At 6 kg the same arithmetic gives $56.00 on sea–rail, $84.00 on economy air, $88.00 on postal air, $104.00 on the battery-friendly shape, $118.00 on the sensitive goods line and $138.00 on priority air — a different order at the cheap end of the list.

When the ranking reverses

Weight is the first reversal trigger. Sea–rail carries the highest fixed band in the register at $26.00 and the lowest per-kilogram rate at $5.00, so it loses at 2 kg and wins from roughly 4 kg upward; by 6 kg it is $28.00 cheaper than economy air. Postal air shows the opposite gradient: competitive on a light parcel, less so once weight accumulates.

Bulk is the second trigger. A parcel that is large and light is billed on volume, which penalises the two shapes that use a divisor of 5000 — priority air and the sensitive goods line — and leaves the 6000 shapes comparatively unaffected. Deadlines are the third. When an arrival date is fixed, spread outranks cost, and a shape with a 22-day range is unusable however cheap it is.

Category is the fourth and least negotiable. A parcel containing installed batteries narrows the field to the shapes that publish acceptance for them, and a parcel containing liquids or magnetic goods narrows it further; cost ranking among the survivors is a secondary question. Where the register marks an entry not verified, that is a statement about this site’s evidence and not about the line’s reliability.

Re-checking the table each cycle

Basket size anchors the comparison to something real. In this site’s 218-listing snapshot taken on 2026-09-29, the median listing is $36.18 and the middle half runs from $22.53 to $53.32; per-lane medians range from $16.87 for headwear to $55.62 for shoes. A 2 kg assumption therefore describes a basket of roughly three to five mid-priced garments, and says nothing about a two-pair footwear order.

The register also changes more often than a printed table can. Re-read the rate field, the divisor and the published window at the start of each shipping cycle, and rebuild the ranking from your own weight rather than from the example above. The comparison tool on this site recomputes spread from the days you type in and flags any line whose range exceeds 10 days, which is the fastest way to see the reliability column move. This note was checked on 2026-09-29.