How to Install Base Kitchen Cabinets
Base cabinets are your foundation—literally. Everything else in your kitchen depends on getting these level, plumb, and solidly secured. Rush this step and you'll have doors that won't close, drawers that slide open, and countertops with gaps. Take your time here. Perfect base installation makes everything else easier.
Quick Summary
Time needed
6-8 hours
Cost
$50-$150 (materials)
Difficulty
Intermediate
Why Level Matters More Than You Think
A cabinet that's 1/4 inch off level doesn't seem like much. But that small error compounds across a 10-foot run. Your countertop won't sit flat. Doors swing open on their own. Drawers slide closed when you're trying to load them. Water pools in one corner of your sink.
Common Mistake: Homeowners think "close enough" is fine because it looks okay empty. Then the countertop fabricator shows up and points out your cabinets are 3/8 inch out of level across the run. Now you're scrambling to re-shim everything before they'll install your $4,000 quartz top.
Professional installers check level constantly—after every adjustment, before every screw. This might feel tedious, but it's the difference between cabinets that last 30 years and ones you're fighting with daily.
Step-by-Step Installation Process
1. Mark Layout and Find High Point
Before moving a single cabinet, you need to know where they go and where your floor is highest.
Transfer Layout to Walls:
- •Mark where each cabinet edge will be
- •Note stud locations at each cabinet position
- •Mark plumbing and electrical locations
- •Draw a level reference line 34.5 inches up (standard countertop height)
Finding the High Point: Set your level on the floor at multiple spots along the cabinet run. The spot where the floor is highest (least gap under the level) is your starting point. All other cabinets will be shimmed up to match this height. Mark this location clearly.
2. Start With Corner Cabinet
If you have a corner, that cabinet goes in first. If not, start at one end of your run—preferably where you found the high point.
Position the Cabinet:
- • Slide cabinet into position against layout marks
- • Remove doors and drawers to lighten it
- • Leave 1/4 inch from wall for irregularities
- • Check that back doesn't hit plumbing or electrical
Level It Perfectly:
- • Place level across front edge (side to side)
- • Shim under low corners until bubble centers
- • Check front-to-back level
- • Shim under back if needed
- • Recheck side-to-side after shimming back
- • Verify cabinet is plumb (use level on side)
Shim Strategy: Use pairs of shims in opposite directions to create stable, adjustable support. Tap gently—you can always add more, but over-shimming lifts the cabinet too high. Check level after every shim adjustment.
3. Secure First Cabinet to Wall
Once perfectly level, anchor this cabinet. It becomes your reference point for all others.
Securing Process:
- 1.Locate studs behind cabinet (you marked these earlier)
- 2.Drill pilot holes through cabinet hanging rail into stud
- 3.Drive 2.5-inch screws through rail into stud—don't overtighten
- 4.Check level again after first screw
- 5.Add second screw if still level
- 6.Use at least 2 screws per cabinet, more for larger units
Pro Tip: Don't fully tighten screws until you've installed adjacent cabinets. You might need to micro-adjust alignment. Snug them enough to hold position but not so tight you can't make adjustments.
4. Install Adjacent Cabinets
Work outward from your first cabinet. Each new cabinet must be level with the ones already installed.
For Each Cabinet:
- 1. Position next to installed cabinet
- 2. Place level across both cabinets
- 3. Shim new cabinet to match height of first
- 4. Check that face frames are flush
- 5. Clamp face frames together
- 6. Verify level one more time
- 7. Secure to wall
Common Issues and Fixes:
5. Join Cabinets Together
Once cabinets are positioned and secured to the wall, join them to each other. This creates one solid run.
Joining Process:
- 1.Clamp face frames together with C-clamps
- 2.Verify frames are perfectly flush
- 3.Drill pilot holes through one frame into the other
- 4.Drive 2.5-inch cabinet screws to join
- 5.Use at least 4 screws per joint (2 top, 2 bottom)
- 6.Remove clamps and check alignment
Smart Move: Pre-drill holes slightly smaller than your screw diameter. This prevents splitting the face frame wood while still allowing screws to grip firmly. Don't skip pilot holes—one split frame ruins the whole joint.
6. Final Checks and Adjustments
Before declaring victory, walk through these final verifications.
Tools and Materials You Need
Essential Tools
- •4-foot level (longer is better)
- •Cordless drill with bits
- •Stud finder
- •C-clamps (at least 4)
- •Utility knife
- •Tape measure
- •Pencil
Materials
- •Wood shims (2-3 packages)
- •2.5-inch cabinet screws (#8 or #10)
- •1.25-inch cabinet screws (for face frames)
- •Wall filler strips (if needed)
- •Toe kick material
Frequently Asked Questions
Do I need to level every cabinet individually?
Yes, every cabinet must be level both front-to-back and side-to-side. Start by finding the highest point of your floor and leveling the first cabinet there. Then work outward, shimming each cabinet to match that level. Cabinets that aren't level will cause doors to swing open, drawers to slide, and countertops to have gaps.
How do I find wall studs for securing cabinets?
Use a stud finder to locate studs behind where cabinets will hang. Mark stud centers on the wall above where cabinets will sit. Studs are typically 16 inches on center. Drive screws through the cabinet hanging rail into studs—never just into drywall. Each cabinet needs at least two screws into studs for secure mounting.
What's the best way to join cabinets together?
Clamp the face frames together first, making sure they're perfectly flush. Drill pilot holes through one face frame into the adjacent cabinet's frame. Drive 2.5-inch cabinet screws to join them. Use at least 4 screws per joint—two near the top and two near the bottom. This creates one solid run and prevents gaps.
Should base cabinets be installed before or after flooring?
It depends on your flooring type. Install cabinets after tile or hardwood that you want to run under them. Install cabinets before floating floors like laminate or vinyl plank, which shouldn't run under cabinets. For kitchen renovations, most pros install flooring first, then set cabinets on top. This makes future cabinet replacement easier.
How many shims do I need for base cabinet installation?
Buy at least 2-3 packages of wood shims (about 50-75 shims total) for an average kitchen. You'll use multiple shims per cabinet, especially if your floor is uneven. Shims are cheap—don't run out mid-install. Place shims under cabinet corners and anywhere the cabinet needs support to sit level and stable.
Ready for the Next Step?
Base cabinets are installed and rock-solid. Now it's time to hang the upper cabinets—which requires even more precision.