Methodology

Last updated: 2026-06-11 · Data verified: 2026-06-11 against the official sources linked below.

Every calculator in the ShipCost Lab portfolio follows the same three rules: the calculation is deterministic (same inputs, same answer, no model guessing), every rate or threshold is traceable to a named source, and the dataset behind each tool carries a visible revision date.

Where the numbers come from

Duty and import-VAT figures are read from the official tariff schedules: the EU’s TARIC database, the US Harmonized Tariff Schedule (USITC), and the UK Online Trade Tariff (GOV.UK). VAT-scheme thresholds and rates (IOSS / OSS, de minimis) come from the underlying EU law on EUR-Lex, the Commission’s Taxes in Europe database (TEDB), and national customs guidance; US trade actions are read from the Federal Register. Carrier dimensional-weight divisors and surcharges come from the carriers’ published rate and service guides. Freight classification uses the NMFTA’s NMFC framework, Incoterms allocation follows ICC Incoterms 2020, and ocean spot-rate context uses the Drewry World Container Index. Each tool cites its specific sources next to the result it produces.

How the data is refreshed

Datasets are reviewed on a monthly cycle. The reference data behind the tools was last verified on 2026-06-11; if a dataset goes more than 30 days without re-verification, the affected tool flags its data as stale rather than presenting it as current. When a regulation changes between cycles (a tariff action, a de minimis change), the affected tool is corrected as the change is confirmed against the official source.

What the tools do not do

The calculators do not scrape live carrier quotes, do not estimate negotiated discounts, and do not produce binding customs valuations. Outputs are estimates built from public, citable inputs — useful for planning and for sanity-checking an invoice, not a substitute for a licensed customs broker or a binding ruling. Where an input is an assumption (an FX rate, a typical brokerage fee band), the tool labels it as such in the result body.

Found a number that disagrees with an official source? Report it to [email protected] with the route and the source you checked — confirmed discrepancies are fixed in the next refresh. Who runs the portfolio is documented on the about page.