What size drawer box for a 24 inch opening?
Side-mount slides need 1/2" a side, so a 24" opening takes a 23" box. The clearances that set the width, depth and height, and box sizes for every common opening.
A 24" opening takes a 23" box on side-mount slides.
6" high and 22" deep, running on a 22" slide.
How that is worked out
- Side-mount ball-bearing slides take 1/2" a side — 1" in total. That figure is the same across essentially every maker, which is what makes the width arithmetic a subtraction rather than a lookup.
- 24" − 1" = 23". Round *down* to the sixteenth, never to nearest: a box a sixteenth wider than the arithmetic said does not go in.
- Depth comes off the cabinet: 23 1/4" of clear depth, less the setback at the front and the clearance at the back, leaves 22" of room — so the longest slide that fits is 22".
Box size by cabinet opening, side-mount slides
| Opening width | Box width | Box height | Box depth | Slide |
|---|---|---|---|---|
| 12" | 11" | 6" | 22" | 22" |
| 15" | 14" | 6" | 22" | 22" |
| 18" | 17" | 6" | 22" | 22" |
| 21" | 20" | 6" | 22" | 22" |
| 24" | 23" | 6" | 22" | 22" |
| 30" | 29" | 6" | 22" | 22" |
| 36" | 35" | 6" | 22" | 22" |
Worth knowing
- Side-mount ball bearing: slide clearance is the one number never to guess. Undermount slides need a different width and a notch in the back of the box, and centre-mount needs different again — check the instructions for the slide in your hand.
- Measure the opening, not the cabinet. In a face-frame cabinet the opening is smaller than the box, and the slide has to be shimmed or mounted on a rear bracket to clear the frame.
- Slides come in even lengths only. Work out the room you have, take the next size *down*, and leave the difference at the back rather than forcing the longer slide in.
- The box height here leaves clearance above and below for a drawer that has to come out past the one over it. An inset drawer or a full-height drawer front changes it.
Work out your own numbers
- Drawer boxes
Box sizes and a cut list from the opening, with the slide clearances rounded the way that still fits.
- Cabinet boxes
A carcass cut list from the finished outside dimensions, face-frame or frameless.
- Cut list optimizer
Lay your parts out on a sheet of plywood and get the cuts in order. Accounts for blade kerf and keeps the grain running the right way.
Related questions
- How much clearance do drawer slides need?
- Side-mount ball-bearing slides need exactly 1/2" on each side — 1" total — and that is consistent enough across makers to design around. Undermount slides are different and usually need the box a little narrower still, plus a notch at the back. Always read the sheet in the box.
- How deep should a drawer box be?
- As deep as the slide you can fit, which is set by the cabinet's clear depth less the front setback and any space you need behind. Slides only come in even lengths, so work out the room and take the next size down. A standard 24" base cabinet usually lands on a 20" or 22" slide.
- Should I round the drawer box width up or down?
- Down, always, to the nearest sixteenth. A drawer box is a thing that has to fit inside something else, so an error in the generous direction is a box that does not go in and has to be recut. A sixteenth of slop at the sides is invisible; a sixteenth of interference is a ruined box side.