When a chair wobbles, don’t try cutting the long legs. Instead, shim the short leg.
Here’s how: Place the chair on a flat surface. Slide a wood shim under the short leg until the chair no longer wobbles.
Use a pencil to trace an outline of the chair leg onto the shim. Cut the shim to size using a hole saw that’s about the same diameter as the chair leg.
Turn the chair upside down and place the shim onto the bottom of the short leg. Hold the shim in place with a furniture glide.
Now install a glide on each of the remaining three legs.