Cabinet Door Calculator

How Shaker Door Construction Works

A Shaker cabinet door is built from five pieces: two stiles, two rails, and a center panel. The stiles run the full height of the door on the left and right. The rails span horizontally between the stiles at the top and bottom, with a tongue on each end that seats into a matching groove cut into the inside edge of the stiles. That same groove also captures the edges of the flat center panel. The joinery is simple, strong, and can be cut with a matched pair of cope-and-stick router bits or on a shaper in about twenty minutes per door.

Measuring for Stiles and Rails

Start with the finished outside dimensions of the door, not the cabinet opening. For inset doors, subtract about 1/16 inch from each edge of the opening. For overlay doors, add the overlay amount on each side. Enter those finished dimensions into the calculator. The stiles are cut to the full door height. The rails are cut shorter than the door width because they sit between the two stiles, but then gain length on each end equal to the tongue depth so they can reach into the stile grooves. The calculator handles this math for you.

Why Panel Clearance Matters (Seasonal Movement)

Solid wood expands and contracts across its grain with changes in humidity. A dry winter shop followed by a humid summer can swell a panel by nearly 1/4 inch across its width. If that panel is glued or pinned tight in the frame, something has to give, and it is usually the joinery or the panel itself. Shaker doors solve this by letting the panel float freely in the frame grooves. Small rubber Space Balls or a thin foam strip in the groove keeps the panel centered while still allowing movement. The default panel clearance of 1/16 inch per side is conservative and safe for most cabinet-scale doors.

Tongue Depth and Groove Construction

Most cope-and-stick router bit sets cut a groove about 3/8 inch deep, which is also the default tongue depth in this calculator. Deeper grooves mean stronger frame joints and more panel support, but they also mean longer rails and a wider panel to match. If you are using a different bit set, measure the groove depth it produces and update the tongue depth field. Keep both numbers equal so the panel and the rail tongues seat fully without bottoming out before the shoulders close.

Frequently Asked Questions

What is a Shaker-style cabinet door?

A Shaker door is a simple frame-and-panel door with two stiles, two rails, and a flat center panel that floats in a groove. It is valued for its clean look and its tolerance of seasonal wood movement.

Why do I need to add panel clearance?

Solid wood panels expand and contract with humidity. Leaving 1/16 to 1/8 inch of clearance on each side gives the panel room to move without cracking the frame.

What's a typical stile and rail width?

Most Shaker doors use stiles and rails 2 to 2.5 inches wide. Larger doors sometimes use 3 inch frames to keep the proportions balanced.

Should the panel be solid wood or plywood?

Plywood is stable and cheap, ideal for painted doors. Solid wood is richer looking but needs movement clearance. Choose based on finish and budget.

How does tongue depth affect cutting?

A deeper tongue produces a stronger joint but requires longer rails and a wider panel. Match the tongue depth to the groove depth cut by your router bit.