How to Install Kitchen Cabinet | Studs, Shims & Level Lines

Installing kitchen cabinets requires finding the floor’s high point, marking level reference lines, locating studs, and fastening each cabinet with shims and screws.

Installing kitchen cabinets is a two-person job that rewards patience over speed. Most installations fail because the floor’s high point is never found, so the entire run drifts out of level. The process breaks down into four phases: prep, layout lines, hanging, and final fastening. The order matters less than the measurements — get the lines right and the cabinets will follow.

Prep: Utilities, Doors, and the Floor’s High Point

Turn off electrical, gas, and plumbing supply lines before touching anything. Water lines and gas connections sit behind walls where you’ll be drilling, and live wires are a shock risk when you cut or fasten into studs.

Remove all doors and drawers from the cabinet boxes — they add weight and make the boxes awkward to carry. Lighter boxes also mean fewer dropped corners. Move every cabinet with two people, never one. Set the boxes near their final location, and clear the countertop area of appliances.

Find the room’s highest floor spot using a long level or straightedge. Lay the level across the floor in several directions and mark the point where it sits highest. That single mark becomes your reference for every vertical measurement. Skipping this step is the most common mistake in cabinet installation — the run drifts, gaps appear, and countertops never sit flat.

Layout Lines: The Numbers That Matter

Mark three horizontal reference lines on the wall before hanging a single cabinet.

• Base cabinet line: 34 1/2 inches above the highest floor point (some guides use 35 inches — pick one and stay consistent)
• Bottom of wall cabinets: 54 inches above the floor
• Top of wall cabinets: 84 inches above the floor

Transfer these measurements to the wall with a level, then draw a continuous line around the room. Mark your stud locations at the same time — they usually sit 16 inches on center, but verify with a stud finder rather than assuming. Record each stud position with a small pencil mark above the line where you’ll see it while working.

Hanging: Corner First, Clamps, and Shims

Start with the corner cabinet — it anchors the entire run. On a diagonal corner unit, install a led-ger board first to support the weight while you work. A 1-inch-by-4-inch ledger screwed into studs at the layout line holds the cabinet steady while you fasten it.

Position the corner cabinet on the ledger, then use shims at the base to bring it level and plumb. Check both directions with a level before tightening anything. The next cabinet goes up beside it — clamp the face frames together with wood clamps so the fronts align perfectly, then join them with 2 1/2-inch, #8 screws through the frame edges.

Drill a 3/16-inch pilot hole through the cabinet back into each stud, top, middle, and bottom rail, then drive 3-inch, #10 screws to pull the cabinet tight to the wall. Work in order: level, shim, clamp, then tighten. Tightening wall screws before leveling leaves cabinets out of plumb, and skipping the clamps leaves mismatched face frames.

Finishing: Adjust, Reattach, and Check Your Work

Reattach doors and drawers only after every cabinet is fastened and level. Check the full run one final time with a level — small shim adjustments at the base fix most dips. Use #10 installation screws for wall mounting and #8 screws for joining cabinet face frames; swapping the two invites stripped holes or weak attachment.

Wall cabinets and tall cabinets use slightly different sequences — some systems require fastening base cabinet rails first — so read the manufacturer’s instructions for your specific cabinet line before starting. If any cabinet sits proud of its neighbor, loosen the wall screws, adjust the shims, and retighten. The face frames should read as one continuous surface.

When the run is square and level, the install is done. The next decision is what goes inside the lower cabinets — organizers, pull-outs, and appliance storage change how the kitchen functions. Our tested appliance cabinet roundup covers the best options for hiding small appliances while keeping them reachable.

One last check: open every door and drawer to confirm nothing rubs. A door that catches on its neighbor means the face frames are slightly off — loosen the joining screws, re-clamp, and retighten rather than living with the drag.