How the numbers are counted

The site header shows two numbers: 27,966,275 parts mapped and 127,489 items. This page shows the calculation behind each. Both are computed from the live graph at every build; nothing on this page is typed by hand.

Items: 127,489

An item is one node in the graph — anything with its own page. Counting them by kind:

Shared parts count once. A ball bearing used in hundreds of machines is one item; its page lists every machine that uses it.

Parts mapped: 27,966,275

This is the rolled-up part count: for each product, walk its bill of materials down to the leaves, multiplying quantities at every level, and sum the leaf quantities. Then sum that over all 3,648 products.

A small example: if a bicycle has 2 wheels and each wheel has 36 spokes, the walk counts 72 spokes. The same multiplication runs through every level of every product — a jumbo jet resolves to several million fasteners, rivets, and components this way, which is why a handful of large machines dominate the total:

By domain

What the quantities are

Flagship quantities are anchored to documented figures where they exist (Boeing quotes about six million parts for a 747; Airbus about four million for an A380, including roughly 40,300 electrical connectors). Mid-tree quantities are engineering estimates for a representative product of each kind. The BOM structure on every page is the audit trail: any number here can be followed down the same tree the counter walks.

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