Kitchen cabinet cut list calculator: sides, tops, backs and shelves

The two cabinets this page works out

Both are plain frameless boxes. The sides run the full height, everything across the cabinet fits between the sides, and a back covers the rear edges. They differ at the top. The base cabinet has a bottom and two rails across the top, because a countertop will cover it. The wall cabinet hangs where its underside is seen, so it has a full top and a full bottom.

What the list leaves out matters as much: doors, drawers, a toe kick or plinth, a face frame, the countertop, the joinery and the hardware. Each of those depends on decisions the form does not ask about — which hinges, how the carcass is joined, what it stands on — and the page does not guess. This is a cut list, not a design.

How the parts are counted

The default base cabinet is 24 in wide and 34 1/2 intall, with sides 23 1/4 in deep, in 3/4 in plywood, with one shelf:

• Two sides, 23 1/4 in × 34 1/2 in.
• A bottom, 23 1/4 in × 22 1/2 in.
• Two top rails, 3 15/16 in × 22 1/2 in. The rails are 100 mm wide in this template whatever the cabinet’s size; that is where the odd sixteenths come from.
• A back, 24 in × 34 1/2 in.
• One shelf, 23 1/4 in × 22 1/2 in.

The default wall cabinet, 30 in wide, 30 in tall and12 in deep, is two sides of 12 in × 30 in, a top and a bottom of 12 in × 28 1/2 in, a back of30 in × 30 in and a shelf the same size as the top.

Of those parts, only the back is as wide as the cabinet. It is also the largest piece, and on a base cabinet it is the part that decides whether the job fits one sheet.

Where the thickness is subtracted

The width you type is the outside of the carcass, across both sides. Every part that fits between the sides — the bottom, the top, the rails and the shelves — is shorter by two thicknesses:

inside width = outside width − 2 × thickness

24 in − 2 × 3/4 = 22 1/2 in. Subtract only one thickness and every one of those parts is 3/4 in too long to go in.

The height loses nothing, because the sides run from the bottom of the cabinet to the top and the horizontal parts sit inside them. The depth you type is the depth of the sides, and the parts between them are the same depth. The back does not sit between anything: it covers the whole rear of the box, so it is the full outside width and height, and it adds its own thickness to the depth. Sides of 23 1/4 in and a 3/4 in back make a box 24 in deep before a door goes on.

Plywood sold as 3/4 in often measures 23/32 in. On the default base cabinet that turns 22 1/2 in into 22 9/16 in for four parts. Measure the sheet, type what you measured, and the list follows.

Overlay or inset doors: what the numbers start from

There are no doors on this list, but the list gives you the two sizes a door is worked out from. A full overlay door covers the front of the carcass, so it starts from the outside size of the box — 24 in wide on the default base cabinet. An inset door sits inside the opening between the sides, so it starts from the inside width,22 1/2 in. On the wall cabinet the opening is also shorter than the cabinet by the top and the bottom, 30 in − 2 × 3/4 =28 1/2 in.

From either starting size, a door is then made smaller by the gaps around it, and those depend on the hinges you use. Their instructions give the numbers; this page does not.

One sheet or two

The default base cabinet uses one 4 × 8 sheet and wastes20.7% of it, counting the offcuts. The first cut is a crosscut 34 1/2 in from the end of the sheet. The piece it frees is 48 in wide, enough for the 24 in back and a23 1/4 in side next to each other, grain running up both. The other61 3/8 in of the sheet is ripped into strips: one gives the second side and the bottom, the next the shelf and the two rails.

Widen the cabinet to 27 in and the page still finds a one-sheet layout. At 30 in it takes 2: a 30 in back and a 23 1/4 in side no longer fit across a 48 in sheet together, and unticking the grain box does not win the sheet back — it is still 2. The layouts come from the same method as the plywood cut calculator, which tries several arrangements rather than every possible one.

Wall cabinets are shallower and fit more easily. The 12 in deep wall cabinet takes one sheet at every width from 12 to 36 in in 3 in steps, wasting 42.6% at the default 30 in.

More than one cabinet

Cabinets in a run share sheets, so the count for a run is not the count for one cabinet multiplied. Two of the default base cabinets together take2 sheets. The default base and wall cabinet together also take 2. To lay out a whole run at once, add each cabinet’s parts to the plywood cut calculatoras one list; the PDF from this page gives you the parts to type.

Mistakes that are easy to make

• Typing the depth with the back included. The depth here is the depth of the sides. For a box 24 in deep over a 3/4 in back, type 23 1/4 in.
• Subtracting one thickness, not two. The bottom, the top, the rails and every shelf come out 3/4 in too long.
• Planning on the nominal thickness. Measure the plywood you bought; 23/32 in is common for sheets sold as 3/4 in.
• Counting the bottom or the top as a shelf. Shelves are the loose parts in between; the number on the form does not include them.
• Forgetting the toe kick. These sides run the full height and the list has no plinth. If the cabinet will stand on a separate base, type the height of the box without it.
• Sizing parts to divide the sheet exactly. Every cut takes a kerf. The form counts it; arithmetic on a scrap of paper often does not.

In millimetres

Switch the units and every size typed is converted. In metric sizes, a base cabinet 600 mm wide and 720 mm tall with 560 mm sides in 18 mm board takes one 2440 × 1220 mm sheet, with a bottom, rails and shelf564 mm long. A wall cabinet 600 × 720 mm with 320 mm sides also takes one sheet.

Before the first cut

Measure the plywood’s thickness, the sheet and your blade’s kerf, and type what you measured. Then read the parts table against the drawing of the cabinet you have in mind: the list is exactly as right as the numbers that went into it.

Questions

How many sheets of plywood does a kitchen cabinet take?

The 24 in base cabinet on this page — 34 1/2 in tall, sides 23 1/4 in deep, 3/4 in plywood, one shelf — takes one 4 × 8 sheet with the grain kept. At 30 in wide it takes two. A 30 in wall cabinet 12 in deep takes one. Two base cabinets together take 2 sheets. Type your own sizes to see where yours land.

How wide is the bottom of a cabinet?

When the bottom sits between the sides: the outside width minus two thicknesses. A 24 in cabinet in 3/4 in plywood has a 22 1/2 in bottom, and the shelves and top rails are the same length. In plywood that measures 23/32 in, they are 22 9/16 in.

Why does the base cabinet have rails instead of a top?

A countertop covers a base cabinet, so this template gives it two rails 3 15/16 in (100 mm) wide across the top instead of a full panel. A wall cabinet is seen from below and inside, so it gets a full top and bottom.

Are doors, drawers or a toe kick included?

No. The list is the carcass: sides, bottom or top and bottom, rails, back and shelves. Doors, drawers, a toe kick, a face frame, the countertop, joinery and hardware are all left out, because each depends on choices the form does not ask about.

How deep is the cabinet with the back on?

The back is applied to the rear edges of the sides, so the cabinet is the depth you type plus one thickness. Sides of 23 1/4 in and a 3/4 in back make a box 24 in deep, before a door.

Can I use millimetres?

Yes. Switch the units and what is typed is converted. A 600 × 720 mm base cabinet with 560 mm sides in 18 mm board comes out of one 2440 × 1220 mm sheet, and so does a 600 × 720 × 320 mm wall cabinet.