Practical tools for measured work
Five-Piece Cabinet Door Calculator
Calculate stile, rail and panel sizes for a rail-and-stile cabinet door, then send parts to a cut optimizer.
width of the frame pieces
how far the panel groove is cut into the frame
clearance per side for wood movement
The two stiles and two rails are the same frame width (64 mm) cut to different lengths - send them to the Linear Cut List Optimizer. The panel is a sheet part - send it to the Plywood Cut Calculator.
How it works
How to use it: enter your door's finished width and height, your frame (stile/rail) width, the panel groove's depth, and a small panel gap for wood movement. This models a standard five-piece rail-and-stile door: two full-height stiles, two rails that run between them with a stub tenon engaging each stile's groove, and a floating panel captured in grooves on all four sides.
Formula.
Stile length = door heightRail length = door width − 2 × frame width + 2 × groove depthPanel width = rail length − 2 × panel gapPanel height = (door height − 2 × frame width + 2 × groove depth) − 2 × panel gap
Worked example. With the defaults (450 × 750 mm door, 63.5 mm frame width, 9.5 mm groove depth, 1.5 mm panel gap): stiles = 2 × 750 mm. Rail length = 450 − 2×63.5 + 2×9.5 = 342 mm (×2). Panel width = 342 − 2×1.5 = 339 mm. Panel span height = 750 − 2×63.5 + 2×9.5 = 642 mm, so panel height = 642 − 2×1.5 = 639 mm.
Limitations
This uses one frame width for both stiles and rails - some cabinetmakers deliberately use a wider bottom rail for visual weight, which this simplified model doesn't distinguish; if you use a different bottom rail width, calculate that piece separately.
It assumes a stub-tenon rail-and-stile joint with a groove-captured floating panel - a very common construction, but not the only one. Cope-and-stick router bit sets, mortise-and-tenon (rather than stub-tenon) joinery, and applied-panel (rather than captured-panel) doors all change these numbers. It does not add cutting allowance for a specific router bit's exact profile, sanding, or a raised panel's bevel - confirm final dimensions against your specific tooling before cutting expensive material.
Frequently asked questions
Why is the rail longer than the visible opening between the stiles?
The rail has a short stub tenon on each end that fits into the stile's groove - that's the "+ 2 × groove depth" in the formula. Without it, the rail would only span the visible opening and wouldn't actually connect to the stiles.
Why does the panel need a gap around it?
Solid wood panels expand and contract across their width with humidity changes. A floating panel with a small gap on all sides can move inside its grooves without splitting the frame or buckling - plywood or MDF panels move much less, but a small gap is still good practice.
Can I use this for a plywood or MDF center panel instead of solid wood?
Yes - the sizing formula is the same either way. You can safely use a smaller panel gap for a sheet-goods panel since it won't move as much as solid wood.
Related tools
Linear Cut List Optimizer
Optimize cutting a list of lengths from stock bars/boards, minimizing offcuts and stock used.
Plywood Cut Calculator
Nest an arbitrary parts list onto sheets to minimize waste, with a visual cutting layout you can print.
Drawer Box Calculator
Size a drawer box from the cabinet opening and slide length, then send the parts to a cut optimizer.
Board Foot Calculator
Calculate board feet and total cost for dimensional lumber.