Cabinet Door Calculator

Cabinet Door Calculator that sizes each door from the face frame opening or cabinet box, then provides the stile, rail and panel cuts, board feet, panels per sheet and hinge count.

Cabinet Door Calculator for Face Frame and Frameless Doors

The Cabinet Door Calculator does two jobs in one pass. It sizes each door from the cabinet opening for overlay, inset or frameless mounting. Then it breaks a rail-and-stile door into a cut list of stiles, rails and panels, with board feet, sheet count and hinges.

Sizes are in inches to the nearest 1/32, with a millimeter option. Stock widths and thicknesses are actual sizes, the numbers you mill to, not nominal lumber names.

Door Size From the Opening

On a face frame cabinet, an overlay door covers the frame by the same amount on every edge. The door is the opening plus that overlay twice.

$$W_d=W_o+2v$$

$$H_d=H_o+2v$$

Here $W_o$ and $H_o$ are the opening width and height measured inside the face frame, and $v$ is the overlay per edge. A 1/2 in overlay therefore adds 1 in each way, not 1/2 in. Entering the total overlay instead of the per-edge figure is the usual reason a first door comes out 1/2 in too big.

A pair of doors splits that width around a center gap $g$, so each door gets half of what is left once the gap comes out.

$$W_d=\frac{W_o+2v-g}{2}$$

For a 30 by 30 in opening with a 1/2 in partial overlay and a 1/8 in center gap, each door is 15-7/16 by 31 in. A single door wider than 650 mm (25-5/8 in) gets a warning, since Blum's hinge counts only reach that width, and splitting the opening into a pair fixes it.

Inset and Frameless Reveals

Inset doors sit inside the frame, so the reveal is subtracted instead of added. Builders on Sawmill Creek and WOODWEB mostly settle between 1/16 and 3/32 in per edge. Some say 3/32 in is what Euro hinges need to swing without rubbing.

A 3/32 in reveal means a single door is the opening minus 3/16 in. For a pair, one WOODWEB contributor takes the opening minus 9/32 in and divides by two, which leaves a 3/32 in gap down the middle. On a 30 in opening that comes to 14.859 in per door, a hair under 14-7/8 in.

Inset doors show every flaw in the frame, so check both diagonals of the opening before cutting parts. One WOODWEB builder calls a frame 1/16 in out of square too far off for an even 3/32 in reveal.

Frameless cabinets have no face frame, so the tool measures the outside of the box instead. Each door is the box size minus the reveal at each edge. A 30 in box split into a pair with a 1/16 in reveal and a 1/8 in center gap gives two doors at 14-7/8 by 29-7/8 in.

In frameless mode, the Cabinet Door Calculator also works out the hinge cup bore. The door overlays the cabinet side by the side thickness minus the reveal, which is 17.5 mm on a 3/4 in side. Blum's rule from the CLIP top catalog sets overlay at 11 mm plus boring distance minus plate height, so that door bores at 6.5 mm on a 0 mm plate.

Rail, Stile and Panel Lengths

Stiles always run the full door height. Rails fit between the stiles, so they lose two stile widths and gain the tenon at each end.

$$R=W_d-2S+2t$$

This is the formula Freud prints for its rail and stile bits, where $S$ is stile width and $t$ is tenon length. The Freud Premier instructions give the stub tenon as 13/32 in (10 mm), so the rail is door width minus two stiles plus 13/16 in.

Measure your own bit's tongue before trusting a preset. The tool starts at 3/8 in, and a Fine Woodworking thread points out that Freud and Whiteside bits cut 13/32 in. On the default door that moves the rail from 11-11/16 to 11-3/4 in.

Freud gives 2-1/4 to 2-1/2 in as the normal stile and rail width for cabinet doors. For stronger joints it suggests extended tenons about half the stile width, so a 2-1/2 in stile takes a 1-1/4 in tenon. The Mortise and Tenon Calculator sizes that joint if you go past a stub tenon.

The panel fills the space between the frame parts plus the groove depth on each side. It then gives back a little clearance so it can move inside the grooves.

$$P_w=W_d-2S+2d-c_w$$

$$P_h=\frac{H_d-(n+1)R_w}{n}+2d-c_h$$

Here $d$ is groove depth, $n$ is the number of panels and $R_w$ is rail width. For a solid wood panel, Freud takes 1/8 in off the width across the grain and 1/16 in off the length. The tool uses 1/16 in each way for plywood or MDF, a convention based on how little sheet goods move.

On the default Shaker door with a 1/4 in plywood panel and 3/8 in grooves, the panel is 11-5/8 by 27-3/16 in. Wide solid panels in humid rooms can need more than Freud's 1/8 in, and the Wood Movement Gap Calculator works that out by species and moisture swing.

Stock, Sheet Count and Hinges

Frame stock is reported as net board feet for every stile and rail at your stock thickness. The two default doors need 2.00 board feet, before any extra for test cuts, defects or snipe. The Board Foot Calculator handles the full lumber order once you add waste.

Flat panels are counted against a 4 by 8 ft sheet with a 1/8 in saw kerf between parts. Panels at 11-5/8 by 27-3/16 in fit 12 to a sheet. For mixed sizes across a whole kitchen, the Plywood Cut List Calculator lays them out together.

The hinge count uses Blum's chart by door height or weight, whichever needs more. Door weight is estimated from typical densities for the frame wood and panel, and each default door comes to about 5.3 lb, so it takes two hinges. Blum adds one hinge for a door over 600 mm (23-5/8 in) wide.

Sizing Shaker and Inset Doors

How much bigger should a cabinet door be than the opening?

An overlay door is larger than the opening by twice the overlay in each direction. A 1/2 in overlay door is 1 in wider and 1 in taller than the opening, and a 3/8 in overlay door is 3/4 in larger each way.

The tool's full overlay default is 1-1/4 in per edge, which adds 2-1/2 in. Doors that meet on a shared frame stile need room for both overlays, so check the stile is wide enough before committing to it.

What gap should two cabinet doors have between them?

The Cabinet Door Calculator defaults to 1/8 in between a pair of overlay doors. Inset kitchens usually match the center gap to the outside reveal, so a 3/32 in reveal all around means a 3/32 in gap down the middle too.

Keeping every gap equal matters more than the exact number. Inset builders on Sawmill Creek point out that uneven gaps around a run of cabinets show far more than a reveal that is a little wide.

How do you size a Shaker cabinet door?

A Shaker door is a flat panel in a square-edged rail and stile frame, so it uses the same math as any other five-piece door. The difference is the panel, usually 1/4 in plywood or MDF instead of solid wood.

Because sheet goods barely move, the panel can fit tighter than a raised solid panel. On the default door, the flat plywood panel is 11-5/8 in wide, while a solid raised panel would be 11-9/16 in under Freud's 1/8 in rule.