Install Kitchen Cabinets and Countertops

1. Find the floor's high point before setting a single cabinet

Run a level or a laser across the full run of floor where base cabinets are going, checking at multiple points along the wall, not just at both ends — a floor can dip in the middle of a run even when both ends read close to level against each other. Mark the highest point found; that's the reference line every base cabinet's top gets shimmed to, with the amount of shim increasing as you move away from that point toward the lower areas of the floor.

2. Lay out the run and let filler absorb what doesn't fit evenly

Run the cabinet run calculator for the wall's usable length once appliance gaps and end panels are accounted for — the calculator fills the run with standard box widths from largest down and treats whatever's left over as filler, which is exactly how a real kitchen gets laid out on paper before boxes are ordered. Decide now whether filler goes at one end, split between both ends, or next to an appliance, since that's a design choice worth making deliberately rather than discovering by accident once boxes are already on order.

3. Set and level boxes from the high point out

Install cabinets starting at the high point marked in step 1 and work outward in both directions, shimming each subsequent box up to match the established level line rather than leveling each box independently against the floor beneath it — leveling independently produces a run of individually level boxes that don't actually line up with each other at the seams, which is a more common and more frustrating mistake than it sounds.

4. Template the countertop only once boxes are secured

Run the countertop calculator using the actual installed run length, including whatever filler width ended up in the final layout — not the wall's nominal length from the original floor plan. A countertop fabricator's own template measurement, taken after cabinets are installed and fully secured, is the number that actually governs a stone or solid-surface order, since even a well-planned layout can shift slightly during leveling and shimming.

5. Plan lighting against the finished cabinet line

Run the recessed lighting calculator once cabinet placement is final, positioning fixtures relative to where upper cabinets and the counter's front edge actually land — a light centered on the original floor plan's cabinet line can end up misaligned with a counter or island whose exact position shifted slightly once the cabinets accounted for the floor's real high point.

Why shims only rescue a run started at the wrong end

Cabinet leveling legs and shims compensate for a low floor by raising a box up to meet a reference line — there's essentially no practical limit to how much a low spot can be built up. There's no equivalent tool for a high spot: a box's toe kick has a fixed manufactured height, and lowering a cabinet into the floor to compensate for a high point means notching the box or cutting into the subfloor, neither of which is a routine fix mid-installation.

Take a 12-foot run where the floor is 3/4 inch higher at one end than the other. Start installing at the low end, set that first box level with a small, reasonable-looking shim, and work toward the high end — by the time the run reaches that high point, the floor there needs the box to sit 3/4 inch lower than the reference line already established, and there's no shim that does that. The box either sits proud of the rest of the run by 3/4 inch, visibly out of line with its neighbors, or the installer has to stop, pull already-set boxes, and restart the whole run from the actual high point. Start at the high point instead, and that same 3/4 inch of variation gets absorbed as an increasing shim stack moving toward the low end — solvable at every single box, in the one direction shims actually work.

What goes wrong when the countertop gets ordered before cabinets are secured

Order a stone or solid-surface countertop off the cabinet run calculator's planned length before boxes are actually installed and permanently fastened, and any shift in the run's real position during leveling — even a small one — means the countertop's edges don't land where the fabricator's cut assumed they would, particularly around sink and cooktop cutouts that need to align precisely with the cabinet openings beneath them. A stone top cut to the wrong dimension isn't a small fix; it's a new slab.

The same problem shows up with filler placement decided too late: settle on filler location only after boxes are already fastened to the wall, and a filler strip that turns out to belong next to the appliance instead of at the wall end means unfastening and repositioning boxes that were already leveled and secured, undoing work from step 3 to fix a decision that belonged in step 2.