Because drawer slides have differing requirements for measurement you’ll want to at least pick the “mount”.
Here’s the most common slide types:
- Side mounts are by far the most popular and as the name implies they mount on the side of the drawer. A side mount requires zero rear clearance on a frameless cabinet and ~1/4″ rear gap on a face frame to fit the rear mounting bracket. And most are 1/2″ side clearance (with the exception of heavy duty slides).
- Meanwhile, undermounts are more advanced and are fully concealed under the drawer. Undermounts typically come one inch shorter as they require room in the back of the slide for a connecting mechanism.
- And bottom mounts are a cross between both and are seen on the bottom side of the drawer.
If you have the skill and are undecided I recommend the undermount slides but they require some precise measurement.
On the other hand side mount slides are easy to measure (usually 1/2″ on each side, or 1″ less than drawer opening).