What Size Drawer Slides Do I Need? A Simple Measuring Guide

Match the slide length to the depth of your drawer box, or go slightly shorter, and never pick a slide longer than the inside of the cabinet. For a drawer that is 22 inches deep, that usually means 22 inch slides, and for a 24 inch cabinet it often means 21 or 22 inch slides once you measure the real opening. Then pick a load rating above what the drawer will hold and leave about 0.5 inch of clearance on each side for side mount slides.

Start with the drawer depth

Drawer slides are sized by length, and that length should follow your drawer box. Measure the drawer from the front of the box to the back, not counting the decorative drawer front if it overlaps the cabinet. If the box is 20 inches deep, a 20 inch slide is the starting point.

If your measurement falls between two sizes, round down to the next slide length. A slide that runs a little shorter than the drawer works fine. A slide that is too short leaves the back of the drawer poorly supported, so do not go much under.

Slides are sold in set lengths, so you rarely get an exact match. Our best drawer slides page lists lengths from 10 in to 22 in, which covers most small and mid-size drawers.

Measure the cabinet too

The cabinet sets the upper limit. Measure the inside depth from the back panel to the front edge of the opening, and check for anything that sticks out, such as a face frame, a rear brace or plumbing in a sink base.

The slide cannot be longer than the cabinet. Many cabinets are sold under a nominal depth, and the usable space inside is smaller than that number. This is why a 24 inch cabinet often takes a shorter slide than you might expect.

Also measure the width. Side mount slides need about 0.5 in of space on each side, so the drawer box must be about 1 in narrower than the opening. In other words, the inside cabinet width minus the outside drawer width should equal about 1 in.

Quick answers for common sizes

Here is how the usual questions work out. These are starting points, so confirm with your own tape measure before you order.

22 inch drawer: choose 22 inch slides if the cabinet interior is at least that deep. If the cabinet is tighter, drop to the next shorter length.
24 inch cabinet: measure the inside depth first. Most often the slide ends up at 21 or 22 inches, because the back and front of the cabinet take up space.
Kitchen cabinets: base cabinets are deep enough for the longest slides on our page, while upper cabinets and shallow drawers usually need shorter ones. Always go by your own measurements.
Narrow, shallow drawers such as a desk or bathroom drawer: look at the 10 to 16 inch range.

Pick the load rating

Once the length is settled, think about weight. Estimate what the drawer will hold, then choose a slide rated above that. The ratings in our lineup run from 50 lb up to 200 lb.

Clothes and linens are fine with 100 lb slides. Pots, tools and files call for the high end. A load rating is a maximum, and a drawer that is regularly packed near that limit will wear out sooner, so leave some margin.

Be aware that the rating can vary with slide length. One 12 in listing in our data states that its 150 lb maximum varies with the length of the slide.

Sizes and ratings in our data

One 12 in side mount listing says it suits drawers with an internal depth of 13 to 15 in, which shows that a slide does not always match the drawer length exactly. Read each listing for its recommended drawer depth.

Slide length	Load rating	What the listing shows
10 in	100 lb	Shortest slide on our page
12 in	55.1 lb to 150 lb	Matte black soft close at 55.1 lb; a galvanized Q235 steel pair at 150 lb; a soft close pair at 100 lb with 1.5 mm steel
16 in	100 lb	Full extension, side mount, 0.5 in side clearance
21 in	100 lb	Undermount soft close kit, 6 pairs
22 in	100 lb to 200 lb	Soft close, full extension; one pack lists 200 lb and 10 pairs

Side mount or undermount

Mount type changes how much space you need. Side mount slides attach to the side of the drawer box and need that 0.5 in gap on each side. Undermount slides sit beneath the drawer, so they do not use side clearance but they do need space below the box and often rear brackets.

Extension and soft close are separate from size. Full extension opens the drawer completely so you can reach the back, and soft close slows the last part of the motion. Not every full extension slide has soft close, so check the spec sheet. For help comparing these features, see our drawer slide comparison.

Measure and install safely

Wear safety glasses when you drill or drive screws, and use a cordless drill where you can to avoid cord hazards. Keep fingers clear of the slide channels, which can pinch. Heavy drawers are awkward to lift out, so get help with a drawer rated near the top of the range. Use screws that are not longer than the material is thick, so they do not poke through.

Measure the drawer box depth, front to back.
Measure the cabinet interior depth and note any obstructions.
Check the gap between the drawer and cabinet sides, and compare it with the 0.5 in per side that side mount slides need.
Estimate the drawer's weight and choose a rating above it.
Choose the slide length that matches the drawer or is a little shorter, never longer than the cabinet.

Frequently asked questions

Can I use a slide that is shorter than my drawer?

Yes, a slightly shorter slide works. Going much shorter leaves the drawer poorly supported at the back.

Do I need to measure the drawer front?

No. Measure the drawer box itself, from front to back. The decorative front that covers the opening is not part of the slide length.

Are drawer slides sold in pairs?

Usually yes. One pair serves one drawer, and some packs include several pairs, such as the 4, 6 and 10 pair packs on our page.

What if my cabinet is exactly 22 inches deep inside?

A 22 inch slide only just fits, and any lip or brace can block it. Consider a slightly shorter slide if anything protrudes.