The boxes are built, the run is laid out on the floor, and it is an inch too long for the wall. Or it stops three inches short. Before anybody reaches for a saw: find out which number is wrong, size the difference, and take it out in the cheapest place there is.
Cabinets do not stretch, and walls do not shrink, so “it doesn’t fit” always comes down to a number somebody wrote down. The good news is that a kitchen run has more give in it than it looks: fillers that are always cut to suit, cabinets that come in three-inch steps, a corner with a little play in it, an open end that can simply stop. The bad news is that the give is not everywhere, and the most tempting fix — cutting a box — is the one that costs the most.
Re-measure first: at three heights, finished wall to finished wall, counting every ¾″ end panel and the corner cabinet’s real footprint — half of all “doesn’t fit” is a measuring error. Then size it. Short by under 3″: widen or add a filler. Long by less than your planned fillers: trim them. Long by more: swap one plain cabinet for the next width down (widths go in 3″ steps) and let a filler take up the change. Don’t cut a frameless box narrower, and never steal from an appliance opening.
Before you change a single cabinet, find out which number is wrong. It takes ten minutes, and about half the time the run fits after all and the plan was right; the measurement was taken somewhere the cabinets will not be.
Write the new numbers down in inches — 143⅜″, not 11′ 11⅜″ — and round down, never up. The measuring chapter has the full routine.
Measuring short — the wall turns out wider than you wrote — is survivable: a slightly wider filler absorbs it and nobody ever knows. Measuring long is the expensive one, because the run does not fit and something has to come out. That asymmetry is the whole reason for rounding down, and for a filler at every end.
Once you trust the measurement, the size of the difference picks the fix. Work from the top of this table down, and take the first fix that works — they are in order of cost.
| The run is… | By | First fix to try | If that won’t do |
|---|---|---|---|
| Too short | Under 3″ | Widen the filler at the wall end, or add one | Split it into a filler at each end |
| Too short | 3–6″ | A 6″ filler, scribed to the wall | A narrow cabinet: a 6″ or 9″ spice pull-out, or a 9″ base |
| Too short | Over 6″ | Swap one cabinet for the next width up | Add a 9″ or 12″ cabinet to the run |
| Too long | Less than the planned fillers | Trim the fillers — that is what they are for | Lose the filler at one end, keep the other |
| Too long | Up to 3″ more | Swap one plain cabinet for the next width down | Take the leftover up in a filler |
| Too long | Over 3″ | Swap two cabinets, or drop a narrow one | Re-plan the wall in the designer |
Base cabinets come in 3″ steps from 12″ to 36″, plus 42″; spice pull-outs at 6, 9 and 12″; full-door bases from 9″. Fillers are 3″ or 6″ and always cut down on site. The full list is on the sizes page.
A well-planned run never adds up to the wall exactly. It leaves a filler at each end against a wall, at every inside corner and beside every tall appliance — typically one to three inches per wall. If your run is long by less than that, there is nothing to re-order. The fillers are simply cut narrower than planned.
The catch is that some fillers are not spare. They are doing a job, and if you trim them below a certain width the job stops being done:
So take the inch from the filler that is doing the least: usually the one at a plain end of a run against a wall with no handle near it.
When the overrun is bigger than the fillers can give, one cabinet has to get narrower. Because widths climb in 3″ steps, dropping one box a size frees exactly three inches, and a filler takes up whatever is left over. The skill is choosing which box.
Then decide where the leftover goes. Put the filler where the eye does not land: at the end of the run against a wall, beside the fridge, or tucked into the corner — not in the middle of a run of doors, where an odd strip between two cabinets reads as a mistake from the doorway.
If the sink has to stay centred under a window, the change has to come out evenly from both sides, or out of the side that is furthest from the window. The sink-under-the-window page works through exactly that arithmetic.
A run that comes up short is the easier problem, and the only question is how to close the gap so it looks like it was always meant to be there.
Uppers follow the base run. If you added a filler below, the cabinet above usually wants a matching wall filler, or the uppers and bases stop lining up at the end of the run.
You can cut almost anything. The question is what you are left with. On a frameless box the answer is very different depending on which direction you cut.
| Cut | Verdict | Why |
|---|---|---|
| Narrower | Avoid | The bottom, the top rails and the back all have to be cut, the door cut and its hinge cups re-bored, and the box re-squared. Drawer boxes and runners are fixed widths and do not shrink at all. You are building a new cabinet out of an old one. |
| Shorter (base) | Possible | The simpler cut, because it is the sides and the door that change. On cabinets standing on adjustable legs, check first whether winding the legs down solves it without cutting anything. |
| Shorter (wall) | Order instead | Wall cabinets come in eight stock heights, from 12″ to 42″. A stock height almost always exists for a soffit, a window or a fridge. |
| Shallower | Specialist | Occasionally done over a pipe chase. It moves the back, the rails and the runners, and the countertop overhang changes with it. |
| Fillers & end panels | Yes | That is what they are for: cut to length, scribed to the wall, every time. |
Whatever you cut, melamine chips along the line on the side the blade exits. Score the cut line, tape both faces, use a fine-tooth blade, and keep the good face where the teeth go in. And remember a cut edge is a raw edge: unbanded particleboard at a cut is exactly where water gets in years later, so it has to be sealed or covered. Chipped melamine and peeling banding deals with the edges.
If a run is out on one wall, look at the corner before anything else. Every cabinet on both walls is measured from it, so an error there travels the whole length of both runs and arrives at the far end, beside the fridge or the doorway, where it gets blamed on the last cabinet.
If the cabinets are not fixed yet, go back to the corner, set it to the reference line, and re-lay the run from there. If they are fixed, take the error out at the far end, where a filler or end panel can absorb it — that is exactly why a good plan leaves margin there.
Wall cabinets come in 3″ steps from 9″ to 36″ and the same fixes apply: trim a wall filler, drop a box a size, add a narrow one. What is different is that the top row has to line up with things below it.
When the uppers are hung and still do not line up with each other or with the bases, it is usually a levelling problem, not a sizing one: the uppers that don’t line up.
Whatever fix you choose, try it on the drawing before you re-order a single box. In the free designer, retype the wall at its real, re-measured length and the run you planned either fits or it does not. Cabinets that overlap each other are painted red in the top view, and the ⚠ Errors list in the top-right of the canvas names every one; clicking a row selects the offender so you can narrow it, move it or delete it. Type a code such as b15 into Filter catalog to find the next size down and drop it in, and 📏 Measure tells you exactly what is left at the end of the run.
Then look at it in 3D from the doorway. A filler that is technically fine but sits in the middle of a run of doors is easy to spot on screen, and impossible to unsee once it is on the wall.
If a cabinet has to change size, change only that one. Re-planning a whole wall to absorb an inch is how a one-box problem becomes a five-box order. Write the new code on the plan, check it in the designer, and keep the original box in its carton until the replacement is on the wall.
Re-measure first, at three heights and from finished wall to finished wall, counting end panels and the corner cabinet’s real footprint. Then size the difference. Under three inches is filler territory. Too long by more than the planned fillers means swapping one cabinet for the next width down. Only cut a cabinet when a filler genuinely cannot do the job.
You can, but on a frameless cabinet it is real cabinetmaking: the sides, bottom, top rails and back all change, the door has to be cut and its hinge cups re-bored, and drawer boxes and runners do not shrink at all. Cabinets come in three-inch width steps, so swapping to the next size down plus a filler is almost always the better answer.
Fillers come three or six inches wide and are always cut down on site, never stretched. A three-inch filler covers most end-of-run and corner gaps; six inches closes a bigger gap beside an appliance or a wall. Past about six inches, a narrow cabinet such as a nine-inch base or a spice pull-out usually looks more deliberate than a wide plain strip.
Look for planned fillers first. If the run has a filler at a wall or beside an appliance, trimming it by an inch is the whole fix. If there is no filler to give, swap one plain cabinet for the next width down, three inches narrower, and add a two-inch filler where the eye will not find it. Never take the inch out of an appliance opening.
At an open end, yes: finish the last cabinet with an end panel and the run simply stops. Against a wall, close the gap with a filler scribed to the wall. An open slot there collects crumbs, looks like a mistake, and leaves the last door or drawer with nothing to clear the wall by.
Between two walls, yes. Plan a filler at each end so the run can be shifted to suit the sink or a window, and so each end can be scribed to its own wall. Two equal fillers also read as intentional, where one wide filler at one end can look like a measuring error.
Yes, and it is usually the cleanest fix. Cabinet widths go up in three-inch steps, so dropping one box a size frees three inches. Choose a plain base or a drawer base in the middle of the run, not the sink base, the corner cabinet or anything that houses an appliance, and redraw the run before you order the replacement.
Because a corner cabinet occupies more wall than its label says. A blind corner such as a BBC36-42 is a 36-inch box that consumes 42 inches of wall once its filler pulls it off the corner. Check the occupied width on both walls, and check that the corner is square: a corner wider or tighter than 90 degrees changes what fits on the second wall.
Order a shorter one rather than cut it. Wall cabinets come in heights of 12, 15, 18, 21, 24, 30, 36 and 42 inches, so there is almost always a stock height that fits under a soffit, over a window or above a fridge. Cutting an upper down means cutting the door and moving the hinges, and the result rarely looks factory.
Retype the wall at its real length, drop in the next size down, and see where the filler lands — before you re-order anything.
Open the free designer →