Six calculators, compared by what they leave out

Start with the number that matters: An omission table across six calculators, including two of ours. The rest of this reading explains how it was produced and where it stops applying.

Six calculators, six omissions

Comparing calculators by their outputs flatters all of them. Comparing them by their omissions is what tells you which number to trust.

Six calculators and their omissions
Calculator	Omits	Consequence
Typical landed-cost calculator	Volumetric weight step	Underestimates freight on bulky parcels
Typical freight estimator	Duty and service fee	Underestimates the total by 10–25%
Typical duty calculator	Freight and service fee	Partial figure that reads as a total
Typical budget planner	Segment breakdown	Cannot explain a deviation afterwards
Our freight tool	Duty, service fee	Deliberate — hands off to the cost tool
Our cost tool	Storage and add-ons	Stated on the page rather than hidden

Assessed by running the same parcel through each calculator and comparing outputs.

The common omission is the volumetric step, and the more dangerous version is applying it silently. A silent application produces a number nobody can reproduce, which is worse than an obvious omission.

Enter a parcel with high volume and low weight.
If freight does not change, the volumetric step is absent.
Then change only the declared value.
If the total does not change, duty is not modelled.

The bill, segment by segment

The census splits the bill into item value, domestic delivery, service fee, international freight, duty and insurance. On a other/stuff order the item averages $34.83, and the five remaining segments together span $7.50 to $74.40.

The six segments, with their sample ranges
Segment	Range	What moves it
Item value	$12.52–$168.48	Catalogue mix
Domestic delivery	$0.40–$3.10	Weight band
Service fee	$1.20–$9.80	Fee model, order value
International freight	$9.20–$15.10 at mid (0.8–2 kg)	Billed weight, lane
Duty	$0.00–$17.40	Declared value, destination
Insurance	$0.00–$2.60	Declared value; optional

Item value is a published figure read from the source listings. The other five are modelled ranges and are labelled as such wherever they appear.

The narrow segments — domestic delivery and insurance — are not worth optimising. Together they rarely exceed 4% of the total, and both are largely fixed once the weight band and the declared value are set.

Where a figure needs checking against the live catalogue, the entries themselves are on the current list on kabosheet.

The comparison, with the constant held fixed

Four lanes and five weight bands produce twenty cells, and the ranking is stable across all of them: economy is cheaper at every weight, by a margin that widens.

Economy against express, US lane
Weight band	Economy	Express	Difference
1.5 kg	$5.90–$9.40	$11.40–$17.20	+$5.50
3 kg	$9.20–$15.10	$17.10–$26.40	+$7.90
5 kg	$14.80–$24.30	$25.30–$39.70	+$10.50
8 kg	$22.60–$36.90	$36.20–$57.10	+$13.60
12 kg	$31.40–$52.80	$48.90–$78.40	+$17.50

Modelled from published tariffs on the collection date.

Cost per day saved is the honest ratio: about $0.69 at 1.5 kg, $1.94 at 8 kg and $2.50 at 12 kg. The premium triples while the saving stays roughly constant.

At 1.5 kg: About $0.69 per day saved — a deadline makes this obvious.
At 8 kg: About $1.94 per day saved — a different week is the better lever.
At 12 kg: About $2.50 per day saved — a second parcel or a later date wins.

Three fee models across eleven agents

Across the eleven agents we checked, fee models fall into three shapes — percentage, tiered and flat. Which one is cheapest depends on your order size, and the difference at $150 is larger than the difference between lanes.

Effective service fee at three order values
Order value	Percentage model	Flat model	Tiered model
$60	$1.80–$4.80	$5.00	$2.40
$200	$6.00–$16.00	$5.00	$8.00
$600	$18.00–$48.00	$5.00	$21.00

Modelled from each agent’s published model. The flat model wins below about $170 and loses above it.

Free storage windows run from 30 to 90 days, and the clock start differs: warehouse check-in at some agents, purchase at others. That difference is worth about a week, which matters more than the window length at the margin.

Published fee table: Whether the model is readable without opening a ticket.
Storage clock start: Check-in or purchase — a week of difference.
Consolidation policy: Whether it is offered, and whether it restarts the packing clock.
Claims documentation: Whether compensation terms are published rather than quoted on request.

What each check is protecting against

The checklist is deliberately short. Eighteen items across five groups is enough to catch the defects that show up in practice, and short enough that it gets used on every order rather than only on expensive ones.

The five groups and what a failure means
Group	Checks	A failure means
Shape and silhouette	4	Wrong item or wrong cut — closer to a return
Colour	3	Judge hue, not brightness; warehouse light is not studio light
Markings and labels	4	Missing tag is a query; wrong tag is a return
Measurements	4	Compare against an item you already own
Packaging	3	Damage in transit — a query now, a dispute later

The thresholds are ours. They substitute for a rule that does not otherwise exist between buyer and warehouse.

The verdict rule: one fail is a return; three queries, or any query on shoes and jackets, is a query; everything else passes. The lower threshold on shoes and jackets reflects how hard those defects are to remedy after shipping.

A verdict you wrote down before looking at the next photo set is worth more than one you reconstructed afterwards.

The six causes of a surprise invoice

Deviation between estimate and final invoice has six identifiable causes. Only one of them — random inspection — has no preventive action.

The six deviation causes, ranked
Cause	Median effect	Preventable
Packing volume	+$3.10	Yes — ask for packed dimensions
Tariff step boundary	One full step	Partly — stay clear of boundaries
Lane substitution	+$3 to +$9	Yes — confirm the lane before paying
Duty treatment	Up to +$17.40	Partly — declare accurately
Consolidation timing	Restarts a 1–2 day stage	Yes — request before packing
Currency settlement	±1–3%	Partly — settle in the quoted currency

Medians from the sample where a deviation was observed. Individual cases differ.

A well-run order deviates by under 5%. Beyond that, one of the six causes above is usually identifiable after the fact — which is the point of listing them rather than treating deviation as noise.

The volumetric step is the largest single cause and the least disclosed. If your estimate came without packed dimensions, it is a lower bound.

The three charges in a return

Three separate charges apply to a return, and only one of them is ever quoted up front. That asymmetry is why change-of-mind returns are more expensive than buyers expect.

Return cost by reason
Reason	Outbound refunded	Return freight covered	Typical total
Confirmed defect	Yes	Usually	$0–$12
Wrong variant shipped	Yes	Usually	$0–$12
Change of mind	No	No	$14–$46
Sizing error	No	No	$14–$46

Paraphrased from published return terms across the agents in the sample; the operator’s own wording governs.

The decision rule is arithmetic, not sentiment: if the round-trip freight exceeds half the item value, the return costs more than it recovers unless the item is unusable.

Check whether the defect is confirmed by the warehouse or only suspected.
Check the return window — most run 7 to 14 days from delivery.
Check whether the category accepts returns at all.
Check whether the item is worth more than the round-trip freight.

What this reading rests on

Three source labels apply across this site, and each figure states which. Nothing is presented without a sample size, because a range without one is an opinion.

Sources by figure type
Figure type	Source label	Sample
Item value	Published	96 listings
Transit stages	Measured	96 orders
Freight ranges	Published tariffs	4 lanes × 5 bands
Duty ranges	Published thresholds	4 destination regions
Fee ranges	Published fee pages	11 agents
Weight bands	Derived from category baselines	96 entries

The weight band assignment is the largest known source of error and is systematic rather than random.

Known biases are stated rather than hidden: bands are assigned rather than weighed, prices were read once, and duty is modelled rather than assessed. Each of those is a real limitation and each is labelled wherever it appears.

Corrections are logged publicly on the errata page, with the date and what changed.

The risks, ranked by cost

Three risks account for most of the money lost in our sample: an inaccurate declaration, an unmeasured packed dimension, and a claim window that closed before the parcel was opened.

Risk ranked by expected cost
Risk	Frequency in sample	Cost when it happens
Packed volume exceeds estimate	31 of 96	+$3.10 median, up to +$11.80
Declaration falls outside threshold	Uncommon	Up to +$17.40 duty
Claim window missed	Rare	Full declared value
Lane substituted without notice	Occasional	+$3 to +$9
Storage exceeds free window	Occasional	Charged in blocks

Frequencies from the sample; costs modelled from published terms.

Ranked by expected cost rather than by likelihood, the declaration sits first: it is uncommon and expensive, which is the worst combination for a risk you can address in a single field.

Measure packed dimensions before the freight payment, not after.
Declare accurately and keep the order record.
Photograph the parcel on the day it arrives, before opening it.
Note the claim deadline in a calendar on the delivery date.