How to Build a Bill of Materials for Handmade Jewelry (With Real Examples)

A bill of materials is a list of everything that goes into a finished piece. In manufacturing, BOMs are table stakes. In jewelry making, most people skip them entirely and price from gut feel, or they build one in a spreadsheet that goes stale the week after they make it.

The result is predictable. You quote a ring at $1,200 because that felt right six months ago. Gold has moved 12% since then. Your stones cost more than you remembered. The findings supplier raised prices. Your actual margin on that ring is now 38% instead of the 55% you thought you were earning.

A proper BOM fixes this. Not because it's complicated, but because it forces you to write down what actually goes into each piece and what each component costs today.

What goes into a jewelry BOM

A jewelry BOM has more moving parts than a typical manufacturing recipe. A furniture maker's plywood doesn't change price four times a day. Yours does.

Here's what belongs in every jewelry bill of materials:

Precious metals

The weight of metal in the finished piece, recorded in whatever unit you work in. Grams and pennyweights are the most common. You need the alloy specified, not just "gold." 14K yellow, 18K rose, and 24K pure are three different costs per gram. (Our karat purity guide has the full breakdown of fineness and cost per gram across alloys.)

Record the fabrication weight, not just the finished weight. A ring that weighs 5.8g finished might need 6.5g of stock to produce, because you lose metal to filing, sanding, and polishing. More on loss factors below.

Gemstones

Each stone by type, cut, size, quality grade, and cost. A 0.75ct round VS1 diamond is not interchangeable with a 0.75ct round SI2. If you're using calibrated stones (melee, accent stones), record the total carat weight and cost per carat. For one-of-a-kind stones, record the individual piece cost. (Our gemstone inventory tracking guide covers what data to store for each stone, when to serialize vs. track by lot, and how to handle consignment parcels.)

Findings and components

Clasps, jump rings, ear wires, prong heads, bezels, chains by the inch. These are usually purchased by the piece or by the gram. Don't skip them because they seem trivial. A 14K lobster clasp runs $18–$45 depending on size and supplier. Four prong heads for a pendant setting might add $30. On a $400 piece, findings can represent 8–12% of material cost.

Consumables

Solder, flux, polishing compounds, investment (for casting), rhodium plating solution. These are harder to allocate per piece, but they're real costs. Most jewelers estimate consumables as a flat cost per piece or as a percentage of metal cost. Somewhere between $2 and $8 per piece is typical for a bench jeweler doing fabrication. Casting operations run higher.

Labor

Your time at the bench. This is where jewelers disagree the most. Some include labor in the BOM. Some keep it separate in their pricing formula. Either approach works as long as you're consistent. If you include it, estimate bench time in hours and assign an hourly rate. A fabricated solitaire might take 3–5 hours. A pave eternity band, 8–12. (Our pricing guide covers how to set your bench rate and build labor into your final price.)

Outsourced operations

Casting fees, stone setting by a contractor, engraving, plating. If you send work out, those costs belong in the BOM. A casting house might charge $35–$75 per piece depending on complexity. A stone setter might charge per stone. These are predictable, per-piece costs that should be line items.

A worked example: 14K yellow gold solitaire ring

Let's build a real BOM. This is a 14K yellow gold solitaire with a 1.0ct round brilliant diamond, fabricated at the bench (not cast).

Component	Qty / Weight	Unit cost	Line total
14K yellow gold (shank + head)	6.5g fab weight	$51.20/g	$332.80
Round brilliant diamond, 1.0ct, G/VS2	1 pc	$4,800.00	$4,800.00
14K 4-prong head, 6.5mm	1 pc	$42.00	$42.00
14K hard solder	~0.3g	$51.20/g	$15.36
Consumables (flux, polish, etc.)	flat		$5.00
Labor (4 hrs @ $75/hr)	4 hrs	$75.00/hr	$300.00

Total BOM cost: $5,495.16

At a 1.8x markup on materials plus labor, this ring prices out around $9,890. At 2.0x, about $10,990. The BOM tells you exactly where you stand. Without it, you're guessing, and the guess gets worse every time gold moves.

Notice the fabrication weight: 6.5g, not the finished weight of roughly 5.8g. That 0.7g difference is metal loss, and it's real money.

Metal loss: the line item most jewelers forget

Every fabrication process loses metal. Filing, sanding, polishing, cutting. Casting loses metal to sprues and buttons (though you recover most of that). The loss percentage varies by technique and by jeweler, but it's never zero.

Typical loss factors:

• Fabrication (bench work): 8–15% of starting weight, depending on the piece and how much shaping is involved
• Casting: 3–5% net loss after sprue recovery. The casting house may charge you for gross metal used, not net.
• Stone setting: 1–3% from cutting seats and adjusting prongs
• Polishing/finishing: 1–2%, more for heavy texture removal

If you're fabricating a ring from 14K wire and sheet, assume at least 10% loss until you've tracked enough pieces to know your actual number. At $51/g for 14K yellow, a 0.7g loss costs you $35.70. On a production run of 20 rings, that's $714 in metal you bought but didn't sell. It has to be in the BOM.

You can handle this two ways. Either increase the material quantity to include the expected loss (the fabrication weight approach in the example above), or add a separate "metal loss" line item calculated as a percentage. The first approach is simpler. The second gives you a visible number to track and improve over time.

A second example: multi-stone pendant with chain

This one has more components. An 18K white gold pendant with a center sapphire, diamond halo, and an included chain.

Component	Qty / Weight	Unit cost	Line total
18K white gold (pendant body)	4.8g fab weight	$64.10/g	$307.68
Oval sapphire, 1.5ct, medium blue, heated	1 pc	$1,100.00	$1,100.00
Round diamond melee, 1.5mm, G/VS	16 pcs (0.32ct tw)	$120/ct	$38.40
18K cable chain, 18"	1 pc	$185.00	$185.00
18K spring ring clasp	1 pc	$28.00	$28.00
Bail, 18K	1 pc	$22.00	$22.00
Casting fee	1	$55.00	$55.00
Stone setting (17 stones)	17	$12/stone	$204.00
Rhodium plating	1	$15.00	$15.00
Consumables	flat		$4.00
Labor (2 hrs @ $75/hr)	2 hrs	$75.00/hr	$150.00

Total BOM cost: $2,109.08

This piece has 11 line items. If you're tracking it in a spreadsheet, every price change means opening the sheet, finding the right cell, updating it, and hoping you didn't miss one. If you make 5 variations of this pendant (different center stones, different chain lengths), that's 5 sheets to maintain. It gets old fast.

Sub-assemblies: BOMs inside BOMs

Some pieces have components that are themselves assembled from parts. This is where BOMs become multi-level.

Take a charm bracelet. The bracelet is the top-level BOM. But each charm is its own sub-assembly with its own materials, stones, and labor. The bracelet BOM references the charm BOMs rather than listing every gram of metal in every charm individually.

Why this matters: if you sell the charms individually and on bracelets, you maintain one recipe per charm. Update the gold cost in the charm BOM, and it rolls up to every bracelet that includes it. Without nesting, you'd update the same gold cost in a dozen places.

Another common case: a bridal set. The engagement ring and wedding band are separate BOMs that can be sold individually or together as a set. The set BOM references both components. Change the diamond in the engagement ring BOM, and the set cost updates automatically.

Spreadsheets can technically do this with cross-sheet references, but maintaining the links as you add pieces and update prices becomes a second job. This is one of the main reasons jewelers outgrow spreadsheets and start looking for dedicated tools. (We cover the broader tooling question in our jewelry ERP guide.)

Keeping BOMs accurate when prices move

A jewelry BOM is only useful if the costs in it reflect reality. That's the core problem: precious metal prices move constantly, and a static BOM is wrong by definition.

There are three approaches, in order of increasing accuracy:

Snapshot pricing

You build the BOM with today's metal price and leave it. This is what most spreadsheet BOMs do. It's accurate the day you create it and progressively less accurate after that. If gold moves 5% in a month, your material cost is off by 5%. On a ring with $330 in gold, that's a $16.50 error. Over a catalog of 40 pieces, the cumulative error starts to matter. (Our COGS tracking guide walks through exactly how this margin erosion compounds.)

Periodic updates

You update your metal costs weekly or monthly. Better than snapshot, but it's manual work. If you have 40 active BOMs across rings, pendants, earrings, and bracelets, updating gold, silver, and platinum costs in each one takes time. Most jewelers start strong with weekly updates and drift to quarterly, then stop.

Live spot-linked pricing

Your metal costs pull from a live or daily spot price feed, adjusted for your alloy and your supplier's premium. When you open a BOM, the cost reflects today's price. When you generate a quote, the margin is calculated against what the metal actually costs right now. This is what Forge does, and it's the only approach that stays accurate without ongoing maintenance.

Common BOM mistakes

After talking with dozens of jewelers about their costing, the same errors come up repeatedly:

• Using finished weight instead of fabrication weight. If your BOM says 5.8g and you actually use 6.5g of stock to make the piece, your cost is understated by 12%.
• Ignoring findings. "It's just a clasp" adds up when you're producing 50 necklaces a month and each clasp costs $25.
• Flat-rating stones. Listing "diamond accent stones: $200" without recording size, quantity, and per-carat cost. When you need to reorder, you don't know what you paid or what to buy.
• Omitting outsourced work. The casting fee and setting labor are real costs. If they're not in the BOM, they're not in your price, and your margin is thinner than you think.
• One BOM per product, not per variant. A ring in 14K yellow and the same ring in 18K white have different material costs. If you use one BOM for both, one of them is wrong.
• Never updating. A BOM from eight months ago might as well be a guess. Gold at $62/g for 18K is a different business than gold at $68/g.

BOM templates vs. real software

A Google Sheet or Excel template is a fine place to start. Build your first few BOMs there, get the structure right, and understand your costs. Seriously. Don't buy software until you know what you need from it.

But spreadsheets hit a wall. The wall comes at different points for different jewelers, but it usually looks like this:

• You have more than 15–20 active BOMs to maintain
• You're updating metal prices in multiple sheets and missing some
• You're making variants (same design, different metals or stones) and duplicating entire sheets
• You want the BOM cost to deduct from actual inventory when you build a piece
• You want a Shopify order to trigger a build that consumes the right materials

At that point, the spreadsheet isn't saving you time anymore. It's a maintenance burden that gets less accurate the busier you get. That's the natural point to move to a tool that connects your BOMs to your inventory and your sales channel.

Forge was built for exactly this transition. Your BOMs pull live metal costs, reference your actual inventory quantities, and connect to Shopify orders through build orders that reserve and deduct materials automatically. When gold moves, every BOM updates. When a Shopify order fulfills, the right materials come off the shelf. No spreadsheet maintenance, no manual updates, no wondering if your costs are current.

For more on how inventory fits into this picture, see our guide to tracking raw materials on Shopify, or our breakdown of what Shopify's native inventory gets wrong for jewelers.

Questions about building BOMs for your pieces? Email hello@startforge.app. We talk to jewelers about this stuff every day.