How to Read Cabinet SKU Codes From B12 to WBC3042

Somewhere between the 3D rendering and the order confirmation, every cabinet kitchen turns into a wall of codes — B18, SB36, W3030, WBC3042 — and suddenly you're expected to sign off on a five-figure quote written in a language nobody taught you. The good news: cabinet SKU codes aren't arbitrary. They're a compact description of exactly what each box is, and once you know the system you can read any brand's quote, catch ordering mistakes before they ship, and check whether the cabinet you need even exists — in about ten seconds per line.

We read these codes all day as an online cabinet dealer, and we field the same decoding questions constantly — what's a WBC3042, is there such a thing as a 30-by-9 cabinet, what do the letters after the numbers mean. So here's the full decoder: the anatomy of a cabinet SKU, every common prefix and suffix, the standard dimensions the numbers assume, and how to use all of it to protect your order.

Table of Contents

• The Anatomy of a Cabinet SKU
• The Standard Dimensions the Numbers Assume
• Letter Prefixes Decoded
• Reading Real Codes, Step by Step
• Suffixes and Modifiers
• Fillers, Panels, and Trim Codes
• Do Codes Change Between Brands?
• How to Check Whether a Size Exists
• Using SKUs to Check a Quote
• Frequently Asked Questions

The Anatomy of a Cabinet SKU

Nearly every framed cabinet brand in America writes its SKUs the same way: letters first, numbers second. The letters tell you what kind of cabinet it is — wall, base, sink base, pantry. The numbers tell you its size, almost always width first, then height, in inches. Depth usually isn't written at all, because each cabinet family has a standard depth that's assumed unless a modification says otherwise.

So W3030 is a Wall cabinet, 30 inches wide, 30 inches tall. B18 is a Base cabinet 18 inches wide — no height digits, because base cabinets all share one standard height, so writing it would be redundant. WBC3042 is a Wall Blind Corner cabinet, 30 inches wide, 42 inches tall. That's the entire trick. Everything else in this guide is vocabulary — the specific letters and the standard dimensions the numbers lean on.

The Standard Dimensions the Numbers Assume

The reason B18 can get away with two digits is that the industry standardized the other two dimensions decades ago. Commit these to memory and every code gets shorter:

Two practical notes. Widths move in 3-inch increments, which is why filler strips exist — they absorb the leftover inches between the last cabinet and the wall. And wall-cabinet height is the one number that always appears in the code, because kitchens legitimately vary: 30″ uppers under soffits, 36″ in standard rooms, 42″ run to the ceiling. When you see four digits on a wall cabinet, read them as width-then-height, every time.

Letter Prefixes Decoded

Here's the vocabulary, grouped the way spec books group it. This covers the overwhelming majority of codes you'll meet on a quote:

Reading Real Codes, Step by Step

Let's decode the exact codes people search for — the ones that probably brought you here:

• SB30. Sink base, 30 inches wide. Standard base height and depth (34½″ × 24″), false fronts instead of working drawers, open interior for plumbing. If your sink is a 30″ farmhouse, note that apron sinks usually need the next size up and a modified front — check the spec book before assuming.
• WBC3042. Wall blind corner, 30″ wide, 42″ tall. The "blind" side slides against the neighboring wall run; you'll specify left or right at order time. Ceiling-height corner uppers like this are how full-height kitchens turn the corner without a diagonal face.
• W3030. Wall cabinet, 30″ × 30″ — the classic over-counter upper for standard-height kitchens with crown above.
• B36. Base, 36″ wide — usually a double door with one or two drawers on top, and in many books the widest standard base before you're into sink-base or corner territory.
• A code like B36 with extra letters after it — B36FH, B36GD, B36-2 — is the same 36″ base wearing a modifier. That's the suffix system, and it's the one place brands genuinely diverge, so it gets its own section below.

And the famous near-miss: the "30 by 9" cabinet. People search for a 30″ × 9″ cabinet because they have a short gap over a window, sink, or fridge. What they're looking for is usually a W3012 (30″ wide, 12″ high) or, in books that carry them, a 9″- or 15″-high bridge cabinet. Not every brand makes every short height — some start bridge cabinets at 12″ — which is exactly the kind of question the spec book answers in one page flip.

Suffixes and Modifiers

The letters after the numbers describe how the cabinet is configured. These are the most common conventions — with the honest caveat that suffixes are where brands freelance the most, so always confirm against the specific brand's book:

• FH — full height. A base with one tall door and no top drawer. Common for sink runs and pull-out applications.
• GD or GLD — glass door. Or a glass-ready opening, prepped for inserts. Some brands sell the glass separately; ask.
• L / R — hinging. Left or right door swing, or the blind side on corner cabinets. Single-door cabinets need this specified; it's the most common thing missing on DIY orders.
• -1 / -2 / -3 (or a trailing digit) — drawer or door count. DB243 in many books means a 24″ drawer base with 3 drawers.
• BUTT — butt doors. Two doors meeting without a center stile on wider cabinets.
• ROT — roll-out tray(s). Either built into the SKU or ordered as a per-cabinet accessory.
• TRD / WB — trash pull-out / waste basket. Configuration codes for the trash cabinet, one of the most-searched accessory SKUs in every brand.
• SDF and similar finish/front codes — brand-specific abbreviations for drawer-front style or interior options. When a suffix isn't in this list, don't guess: it's defined on page one or two of that brand's spec book, and guessing wrong is how a slab-front kitchen arrives with five-piece drawers.

Fillers, Panels, and Trim Codes

A finished kitchen needs parts that aren't cabinets, and they carry codes too. BF3 / WF3 / TF3 are base, wall, and tall fillers, 3 or 6 inches wide, scribed to close wall gaps. BEP / WEP / TEP (or REP for refrigerator) are end panels that skin the exposed side of a run. TK is toe kick, sold in long strips. Crown and light-rail moldings carry per-brand names and profiles. None of this is glamorous, and all of it is why an itemized quote that shows only cabinet lines isn't finished — a kitchen without its trim codes is a kitchen waiting on a second freight charge.

A Quick Word on Vanity and Specialty Codes

Bathroom codes trip people up because the numbers look familiar and the assumptions aren't. A VSB30 is a vanity sink base 30″ wide — but at 21″ deep and (depending on the line) 34½″ comfort height or the older 31½″ standard, it is not a kitchen SB30 with a different letter. Put a kitchen base in a bathroom and you gain 3″ of depth the room may not have; put a vanity base in a kitchen and your countertop dies 3″ short of the wall. The same check-the-assumptions rule applies to desk-height bases, wine racks, appliance garages, and wall cabinets sold as laundry uppers — the code style is identical, the standard dimensions aren't.

Specialty units also carry the most brand-specific codes in the book: microwave shelves, oven towers with cutout specs, furniture toe options, wainscot panels. Treat any specialty code as a prompt to read its spec-book page in full, because these are the cabinets where a wrong assumption costs an appliance return, not just a filler strip.

Do Codes Change Between Brands?

The logic is universal; the dialect varies. Width-then-height, letters-for-type, 3-inch increments — that's industry-wide. But one brand's easy-reach corner is another's EZR and a third's BLS; drawer-count digits attach differently; and available heights genuinely differ, especially on bridge cabinets, short uppers, and tall-cabinet heights. Frameless lines add their own wrinkle, since interior dimensions and filler needs change when there's no face frame eating into the opening.

This is why we host every brand's current book on our spec books page — Fabuwood, KCD, Cubitac, J&K and the rest, free, no email gate. When a code on a quote doesn't match what this guide predicts, the brand's own book wins, always. Ten minutes with the right PDF beats any generic decoder, including this one.

How to Check Whether a Size Exists

The exact-size search — "does anyone make a 33-inch sink base with drawers," "is there a 30 by 9 cabinet" — has a reliable three-step answer. First, translate your need into the code system: type letters plus width, plus height if it's a wall or tall unit. Second, open the brand's spec book to that cabinet family and scan the size run; books list every width the line offers, so absence from the page is your answer. Third, before giving up on a missing size, ask about modifications — depth reductions, height cuts, and increased-opening mods can turn the nearest standard SKU into the size your wall needs, usually for less than a custom cabinet.

And if you'd rather not do any of this yourself: that's literally what our free 3D design service is for. Send measurements, and a designer who reads spec books for a living returns a layout where every SKU exists, fits, and opens the right direction.

Using SKUs to Check a Quote

Here's where the decoder pays for itself. When a quote arrives — from us or anyone — run four checks. Match counts: the number of cabinet lines should match the number of boxes in your rendering. Spot-check sizes: pick three codes and verify width and height against the drawing; transposed digits (W3630 for W3036) are the classic ordering error. Check the hinging: every single-door and corner cabinet should carry an L or R. Confirm the trim block: fillers, panels, toe kick, and molding lines present and itemized. A supplier whose quote survives those four checks is quoting carefully; one whose quote can't be decoded at all is asking you to buy a kitchen on faith.

SKU literacy also makes cost conversations concrete. It's how you see that one 36″ base replaces two 18″s for less money, or that a bank of drawer bases is where the budget went — the design-level savings we walk through in our cabinet cost guide come down to exactly these line items.

Frequently Asked Questions

What does WBC3042 mean?

Wall Blind Corner cabinet, 30 inches wide, 42 inches tall. The blind side tucks against the adjacent cabinet run in the corner, and you specify left or right pull when ordering. It's the ceiling-height version of the corner upper.

What is an SB30?

A 30-inch-wide sink base: standard 34½″ height and 24″ depth, false drawer fronts, and an open interior for plumbing. The most common sink base sizes run SB24 through SB42 in 3-inch steps, but check your sink's minimum-cabinet spec — undermounts and farmhouse sinks often need more width than the sink dimension suggests.

What do the numbers in a cabinet SKU mean?

Width first, then height, in inches. Base cabinets usually show width only, because their height (34½″) and depth (24″) are standardized. Wall and tall cabinets show both numbers because their heights genuinely vary. Depth is almost never written — it's assumed by cabinet family unless a modification changes it.

Are SKU codes the same across all cabinet brands?

The structure is — letters for type, width-then-height, 3-inch width steps. The specific letters and suffixes vary by brand, and so do available sizes, especially short bridge heights and corner solutions. When in doubt, the brand's own spec book is the authority; we host the current books free on our spec books page.

What does a suffix like FH, GD, or a trailing number mean?

Configuration: FH is a full-height door (no top drawer), GD is a glass or glass-ready door, L/R sets the hinge or blind side, and a trailing digit usually counts drawers. Unfamiliar suffixes are brand-specific — look them up in that brand's book rather than guessing, because suffix errors ship as real, wrong cabinets.

Does anyone make a 30x9 cabinet?

What you're describing is a 9-inch-high bridge cabinet, 30 inches wide — used over windows, sinks, and fridges. Some brands offer 9″ or 12″ bridge heights; others start at 12″ or 15″. Check the wall-cabinet pages of the spec book for the brand you're pricing, and if the exact height doesn't exist, a height-modified W3012 is often the workaround.

How do I find out if a specific cabinet size exists in a brand?

Open that brand's spec book to the cabinet family and read the size run — every offered width and height is listed. If your size is missing, ask about modifications before assuming custom: depth and height mods on the nearest standard SKU solve most "missing size" problems at semi-custom money.