What is a Bill of Materials (BOM)? A Guide for Artisans and Crafters (2026)

Ask a factory manager how much it costs to make a product and they will pull up a document called a Bill of Materials. Ask most makers the same question and you will get a shrug, a guess, or a spreadsheet that hasn’t been updated since last spring. Yet a candle, a bar of soap, or a leather wallet has a recipe just as precise as any factory product. Learning to write it down properly is the single biggest step from hobby to business.

What is a Bill of Materials? (Plain-English Definition)

A Bill of Materials (BOM) is a structured list of every raw material, component, and packaging item required to make one unit of a finished product, along with the exact quantity and unit cost of each.

In manufacturing, BOMs drive purchasing, production planning, and cost accounting. In a craft business, you already have one in your head: you know that an 8 oz candle takes roughly 200 grams of wax and a splash of fragrance. The difference is that a real BOM is written down, measured, and priced, so it can answer three questions instantly:

• What does one unit cost me to make? (your material cost of goods sold)
• How many units can I make with what is on my shelf? (your production capacity)
• What do I need to reorder, and when? (your purchasing plan)

Makers often call a BOM a recipe, and that’s exactly what it is. In MakerSync, every product and variation has a recipe that works as its BOM.

The 4 Building Blocks of a Maker’s BOM

1. Raw Materials

These are the ingredients that physically become your product: wax and fragrance oil, base oils and lye, chain and gemstones, leather and thread. List each one separately, including the small items. A wick sticker costs pennies, but across 2,000 candles a year those pennies add up to real money.

2. Unit Conversions

Suppliers sell in bulk units, but you use materials in small ones. You buy soy wax by the 10 lb bag and pour it by the gram. You buy chain by the foot and cut it by the inch. Your BOM has to bridge that gap with a cost per usage unit:

Watch out for fluid ounces vs. weight ounces. An “8 oz” candle jar is measured in fluid ounces of volume, but wax is measured by weight. Because wax is less dense than water, an 8 fl oz jar holds only about 7 oz (roughly 200 g) of wax. Mixing the two units is one of the most common causes of costing errors, so pick grams for everything you weigh and stick with it.

3. Wastage (Scrap) Factors

No batch converts 100% of its materials into sellable product. Wax clings to the pouring pitcher, soap loaves get trimmed and beveled, chain gets cut with offcuts, and leather hides have scars, brand marks, and awkward edges. A professional BOM adds a wastage percentage on top of the measured quantity:

• Candles: 3–5% on wax and fragrance oil
• Cold-process soap: 3–8% for trimming, beveling, and test bars
• Jewelry: 3–5% on chain and wire offcuts
• Leathercraft: 15–30% hide yield loss, depending on pattern layout and hide grade

4. Packaging & Finishing

Labels, belly bands, gift boxes, polishing cloths, and safety warning stickers belong in the BOM, not in a vague “overhead” bucket. They are consumed one per unit, so they are a direct material cost. (Shipping mailers that vary by order size can stay in overhead, as covered in our handmade pricing formula guide.)

BOM Examples Across 4 Craft Verticals

Here is what a complete, priced BOM looks like for four of the most popular handmade categories. Supplier prices are realistic 2026 estimates. Swap in your own numbers to get your true cost.

Single-Level vs. Multi-Level BOMs

The candle, necklace, and wallet above are single-level BOMs: raw materials go straight into the finished product. Many makers, however, build products from sub-assemblies, which are intermediate items you make first and use later. That calls for a multi-level BOM.

Soap is the classic example. You don’t make one bar at a time. You make a batch, cut it into bars, cure them, and then sell them individually or bundle them into gift sets:

Other common sub-assemblies include beaded components reused across several jewelry designs, pre-dyed and cut leather panels, and wax melt blends poured into both candles and melts. In MakerSync, you can model a sub-assembly as a Finished Good made to stock: produce the batch ahead of time, and orders draw from that stock before touching raw ingredients.

Why Spreadsheets Break Down for BOM Tracking

A spreadsheet is a perfectly good place to write your first BOM. It’s a poor place to run one. As soon as you have more than a handful of products, the cracks show:

• Shared materials multiply the work: one fragrance oil might appear in 12 product variations across three sizes. Change its price and you have to find and fix every formula that references it.
• Stock never deducts itself: a spreadsheet doesn’t know an Etsy order just used 200 g of wax. Someone has to type that in, every time.
• No link to sales: you can’t see which products are actually profitable this month without exporting orders and running VLOOKUPs.
• Silent errors: one dragged formula or overwritten cell quietly corrupts your costing, and you only find out when your bank balance doesn’t match.

We dig deeper into this in Why Spreadsheets Are Killing Your Handmade Business.

Automatic Margin Recalculation When Supplier Prices Change

This is where a live BOM pays for itself. Imagine your wax supplier raises the price of a 10 lb bag from $28 to $34. That works out to $0.0062/g becoming $0.0075/g. Here is the impact across a typical candle line:

A single supplier invoice quietly removes over a thousand dollars a year from your profit, and that’s only one ingredient. Fragrance oils, jars, and shipping supplies all drift upward too. If your BOM lives in a static spreadsheet, you may not notice for months.

With recipes in MakerSync, you update the ingredient’s cost price once. Every recipe that uses it recalculates instantly, and you can see which products have slipped below your target margin. Then use the free pricing calculator to decide on your new retail price.

Batch Production & Cure/Lot Tracking

Most makers produce in batches, not one unit at a time. A batch-aware BOM workflow keeps your inventory honest and your products traceable:

• Scale the recipe to the batch: pouring 24 candles? Your BOM multiplies out to 4,800 g of wax, 384 g of fragrance oil, 24 wicks, and 24 jars. Check that you have everything before you start melting.
• Assign a batch code: a simple format such as LAV-261005-01 (product, date, sequence) on every label lets you trace any complaint back to a specific pour.
• Record supplier lot numbers: log the lot number of each fragrance oil, essential oil, and colorant used. If a supplier issues a recall or an IFRA documentation update, you know exactly which batches are affected.
• Track cure dates: cold-process soap needs 4–6 weeks and soy candles typically benefit from 1–2 weeks of cure. Record a “ready to sell” date so uncured stock never ships early.
• Compare expected vs. actual yield: if your BOM says a loaf yields 10 bars but you consistently get 9, your wastage factor is wrong, and so is your cost per bar.

MakerSync supports this workflow by letting you produce Finished Goods in batches ahead of time and log production waste as its own inventory movement. You can see how much material went into sellable products and how much was lost along the way.

How to Build Your First BOM in 5 Steps

1. Pick your best-seller. Start with the product that drives the most revenue.
2. Weigh everything during your next batch. Use a scale with 0.1 g precision and write down every material, including labels and stickers.
3. Convert supplier prices to usage units. Divide the invoice price (including shipping) by the total grams, inches, or square feet purchased.
4. Add a wastage factor. Start with the ranges above, then refine using your actual batch yields.
5. Connect it to your sales. A BOM only becomes powerful when every order automatically consumes it. That’s how you get real-time stock levels and true profit margins per sale.

Frequently Asked Questions