Drawer Slide Sizing Calculator

Length, load rating, and clearance for side-mount, under-mount, and center-mount slides.

Drawer setup

Outside-to-outside depth of the drawer box.

Clothes drawer: 15-25 lb. Tool drawer: 50-100 lb. File drawer: 30-50 lb.

Dovetailed: 0.5" (after machining). Box joint: 0.5"+. Butt joint: 0.75".

Recommendation

Slide length
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Standard sizes: 12", 14", 16", 18", 20", 22", 24", 26", 28"
Slide width
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Load rating needed
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Side clearance
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Slide types compared

Sizing rules

Load rating reality check

The "load rating" on a slide box is the maximum static load. In practice:

For a clothes drawer rated 75 lb static, the practical working load is about 40-50 lb. Plan accordingly.

Soft-close mechanism

Soft-close slides use a hydraulic damper that catches the drawer in the last 1-2" of travel and gently pulls it closed. They cost more than standard slides ($20-50 per pair extra) but:

Soft-close slides require precise drawer box dimensions — too tight and they bind, too loose and they don't engage the damper. Most need 1/2" to 3/4" side clearance.

Common drawer slide mistakes

How to mount side-mount slides

  1. Mount the cabinet member first. Use a spacer block to set the right height from the cabinet bottom.
  2. Separate the drawer member. Most slides come apart — pull the inner rail forward and off.
  3. Mount the drawer member on the drawer box. Align flush with the front edge.
  4. Reassemble the slide and test fit. Make adjustments to centering before final screws.
  5. Install the drawer face after the box is mounted and sliding smoothly.

Frequently asked questions

Why is my drawer binding on one side?

Either the slide is mounted slightly off (one side higher than the other), or the drawer box is twisted. Loosen one slide and re-align.

Can I use the same slide length for shallow and deep drawers?

Yes — slide length determines the cabinet depth it fits in, not the drawer depth. You can have a 16" slide with a 14" drawer box.

What's the difference between 32mm and traditional slide mounting?

32mm system uses pre-drilled holes in cabinet sides, spaced 32mm apart. This is the European cabinet standard. Most quality side-mount slides are now 32mm-compatible.