# BOM builder: bill of materials with cost roll-up and CSV

> Build a multi-level bill of materials in your browser: parts, materials, processes and costs roll up to a unit cost, with top cost drivers and a CSV download.

Source: https://sourcesquid.co/tools/bom-builder/

Planning tool · free

# BOM builder. See where the cost sits.

A bill of materials (BOM) lists every part, material and process needed to make one finished product, with quantities per parent and costs. Edit the example or start your own and this builder rolls costs up through three levels, shows the cost per unit and per batch, ranks the top cost drivers and exports a CSV.

  * __Free, no sign-up
  * __Runs in your browser
  * __Save as PDF or email it

Cost per finished unit**$0.00**

Batch cost**$0**

Lines in the BOM**0**

Cost by sub-assembly

Top cost drivers

[Want a BOM-level should-cost from a principal? Get a free teardown in 48 hours](https://sourcesquid.co/start/?from=bom-builder)

**Saved.** Want a copy in your inbox or on WhatsApp as well? Optional.

How it works

## Three steps. One clear answer.

  1. 01

Replace the example rows with your parts: level, part number, description, material, process, quantity per parent, unit, unit cost and preferred region.

  2. 02

Add, remove or move rows; set the level to 1 or 2 to place a part under the assembly above it.

  3. 03

Read the cost per finished unit, the batch cost and the top cost drivers, then download the CSV or copy the BOM as text.

Method and sources

Each row's parent is the nearest row above it with a lower level. Quantity per finished unit = quantity per parent × the quantity per finished unit of its parent (level-0 rows use their own quantity). Extended cost = unit cost × quantity per finished unit. Rolled-up cost of an assembly = its own extended cost + the extended costs of every row below it until the next row at the same or a higher level. Cost per finished unit = the sum of all extended costs; batch cost = cost per unit × units to build. Costs are ex-works material and conversion costs, before freight, duty and margin.

Results are estimates to support your decisions. For binding figures, ask our team or your customs broker.

BOM builder questions

## Straight answers.

Anything else, ask us directly. A principal replies, not a bot.

[anirudh@sourcesquid.co](mailto:anirudh@sourcesquid.co)

### What is a multi-level BOM?

A BOM that nests parts under the assemblies they belong to. Level 0 is the finished product, level 1 its sub-assemblies and direct parts, level 2 the parts of each sub-assembly. It shows both what to buy and how the product is built.

### How do I enter a part used in fractions, like a carton for 24 units?

Enter the quantity per parent as a decimal: one carton for 24 bottles is 1 ÷ 24 = 0.0417 cartons per bottle. The cost then spreads correctly across units.

### What should the unit cost of an assembly be?

Only the cost added at that step, such as assembly labour, coating or packing. The parts below it are added automatically in the rolled-up cost, so they are not counted twice.

### Can I open the CSV in Excel or Google Sheets?

Yes. The file is UTF-8 CSV with a header row, including quantity per finished unit, extended cost and rolled-up cost for each line.

Use it with

## Tools that work well together.

[Cost**Should-cost** Should-cost is the price a well-run factory could reasonably charge for a part, built up from material, machine time, tooling, finishing, packaging, overhead and a fair margin.](https://sourcesquid.co/tools/should-cost/)[Cost**Teardown cost** A teardown cost estimate rebuilds a finished product's price from its parts, assembly labour, packaging, overhead and supplier margin.](https://sourcesquid.co/tools/teardown-cost/)[Cost**Make or buy** A make-or-buy decision compares the total cost of producing a part in-house, including upfront investment and fixed running costs, with the landed cost of buying it from a supplier.](https://sourcesquid.co/tools/make-or-buy/)[Cost**Landed cost** Landed cost is everything you pay to get a product to your warehouse: the factory price plus freight, insurance, import duty, customs fees and local charges.](https://sourcesquid.co/tools/landed-cost/)

From numbers to factories

## Turn this result into a free teardown.

Send one drawing, photo or quote. A principal returns how it is made, where it is made best and a realistic target price, free, in 48 hours.

[Get my free teardown](https://sourcesquid.co/start/?from=bom-builder)[Talk to a principal](https://sourcesquid.co/contact/)