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Wood, Deck & Fence

Drawer Box Calculator

Size a butt-jointed drawer box from opening width, slide clearance, box depth, side thickness, and inset bottom grooves.

Free to useUS & metric displayFormula and worked example below

Layout and stock dimensions

US customary measurements. Prices are in USD.

in
in
in
in
in
in
in

Calculation breakdown

  • All four vertical pieces are 6 in tall. Front/back fit between full-length sides.

Layout model and usable dimensions

Drawer box sizing begins with the clearance required by the actual slide hardware. This calculator subtracts side clearances from the cabinet opening, then produces a simple butt-jointed box cut list with front and back pieces fitted between the full-length sides. It also sizes a bottom panel captured in grooves, using your groove depth and fitting clearance. The drawer face is a separate part and is not included. Verify all slide requirements, including setback, rear bracket space, bottom clearance, and mounting positions, before cutting. Undermount hardware often needs a different box design.

Fit, direction and offcut constraints

  • The bottom panel thickness and groove position are separate decisions and must suit the load and material.
  • Dovetail, rabbet, locking-joint, and undermount systems can change the part dimensions. This output is for the stated butt joint.
  • The decorative drawer front is sized to cabinet reveals separately from the functional box.

Layout arithmetic and example

Outside width = opening − twice side-slide clearance; front/back length = outside width − twice stock thickness; bottom size = inside size + twice groove depth − fitting clearance.

A worked example

A 24 in opening with 1/2 in slide clearance each side gives a 23 in outside box. With 1/2 in sides and 20 in depth, front/back lengths are 22 in and the grooved bottom is 22.4375 × 19.4375 in.

Measure and compare a layout

  1. Read the slide manufacturer’s box clearance requirements.
  2. Choose outside depth, side height, and actual stock thickness.
  3. Confirm the butt-joint arrangement and bottom groove before using the cut dimensions.

Frequently asked questions

How wide should a drawer box be for side-mount slides?

Subtract the clearance required on both sides by the exact slide model from the cabinet opening width.

Does this work for undermount slides?

Not as a universal design. Undermount systems can require special bottom setbacks, notches, and width deductions.

Why is the bottom larger than the inside opening?

A captured bottom extends into grooves in all four sides. Groove depth is added before subtracting a small fitting clearance.

Calculation method: JICWH methodology. Examples are planning assumptions, not product recommendations.

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