How to Measure a Kitchen for New Cabinets: A Step-by-Step Guide

A kitchen measure is the one job on a fit-out where a small mistake doesn't stay small. Get a wall length wrong by 10mm and you're not just redrawing a layout, you're re-cutting panels, re-ordering edge band, and explaining the delay to a client who's already living without a kitchen for another week. The good news is a proper measure isn't complicated. It just needs to happen in the right order, with the right tools, and checked twice before any of it goes anywhere near a cutting list.

Most of the kitchens that end up with gaps, wonky end panels, or a worktop that visibly slopes weren't measured badly out of laziness. They were measured in a rush, in the wrong order, with only one number taken where three were needed. This guide walks through the full sequence a careful fitter actually uses, step by step, with the real numbers behind each one.

1Get the right tools before you walk in

A steel tape, at least 8 metres, not a cloth one. Cloth and fibreglass tapes stretch under their own weight over a few metres, and that stretch is enough to throw off a long wall by several millimetres without you noticing. You'll also want a 1200mm spirit level, a laser level if you've got one, a pencil, a notepad or clipboard that can take a scribble while you're on your knees, and graph paper or a tablet for the sketch. Laser distance measures are fine for an overall room length but get fiddly and less accurate on short runs, like the gap beside a window reveal, so keep the steel tape for anything under a metre or so.

2Sketch the room before you measure anything

Draw the floor plan first, roughly to scale, before a single measurement goes down on paper. Mark every door, window, socket, switch, boiler, stopcock, radiator, and any boxed-in pipework. Number each wall (Wall 1, Wall 2, Wall 3) so your written notes match the sketch later, and note which way the sketch is oriented, because a kitchen with an island or a dog-leg layout gets confusing fast once you're back at the van trying to remember which number belonged to which wall.

3Measure every wall at worktop height

Take wall lengths at roughly 900mm up, the height a worktop sits at, not at skirting board level and not at head height. Skirting boards are often thicker than the wall above them, and old lath-and-plaster walls can bow in or out above head height, so a reading taken at the wrong level will mislead you either way. Record every measurement to the nearest millimetre, in millimetres only, not metres and centimetres mixed together on the same page. "2438mm" on a cutting list is unambiguous. "2.4ish metres" is how call-backs happen three weeks later.

4Measure openings and trims as their own segments

For any wall with a window or door, measure from the corner to the outer edge of the architrave or trim, not to the window frame itself. Cabinets, and especially an end panel, need to clear the trim, not just the opening behind it. Then measure each segment of that wall separately, corner to trim, trim to trim, trim to corner, and add them up. If your segment total doesn't match the overall wall length you took in step 3 to within about 2-3mm, something's off, and you need to re-measure before you move to the next wall, not after you've finished the whole room and lost track of where the error is.

5Check every corner for square, don't assume it

Use the 3-4-5 method, scaled up for a kitchen: mark a point 900mm along one wall from the corner, mark a point 1200mm along the adjacent wall from the same corner, then measure the straight line between those two points. If it comes back at 1500mm, the corner's square. If it's off by more than about 5-10mm, note it on your sketch now, with the actual figure, not just a tick that says "a bit off". A corner that's out by 15mm over a run of cabinets is the difference between a filler panel that looks like a deliberate design choice and a gap that looks like someone made a mistake.

6Check the walls for plumb, not just the corners for square

Hold the spirit level flat against each wall, vertically, in a couple of spots along its length, top and bottom. Older houses especially can lean 10-20mm over a 2 metre run without it being at all obvious to the eye. A wall that's out of plumb will throw your worktop line level even if every single cabinet is sitting perfectly level on the floor, because the wall is what the cabinet backs and fixing screws rest against. This is the single most common reason a finished run looks slightly off even though every carcass that went into it was built dead square on the bench.

7Measure the height at more than one point

Check floor-to-ceiling height in at least three spots along a run, not just the middle. Older ceilings especially can vary by 10-15mm from one end of a kitchen to the other, and a sloped or coombed ceiling under a staircase or in a loft conversion can vary a lot more than that. Always design to the lowest measurement you find, not the average and not the highest one. It's a lot easier to leave a small, deliberate gap above a wall cabinet on the tall end of a run than to discover on install day that a cabinet won't physically go up on the low end.

8Check the floor for level before you set a base cabinet height

Run the spirit level across the floor in both directions, along the run and across it, not just in one spot near the sink. A floor that drops 10mm over 3 metres is common in older houses and isn't a problem by itself, but it changes how you pack and shim base units so the worktop line stays dead level across the whole kitchen. Note the highest point on the floor along the run, because that's the point every cabinet height gets measured and packed from.

9Mark every utility point exactly, with numbers

For the sink, measure from the nearest corner to the centre of the waste outlet, not to the edge of the existing unit, which may well move. Do the same for gas points, the dishwasher's water and waste connections, and any socket that a new cabinet might land directly in front of. "Roughly in the middle" is not a measurement anyone can cut a hole from. Write down an actual distance from a fixed point, because that corner is still going to be there when the new cabinets go in and the old sink and its unit are long gone to the skip.

10Record appliance sizes and door swing, not just the gap

For every integrated appliance, note the actual width, depth, and height of the unit itself, plus which side its door or drawer opens on. A dishwasher that's 596mm wide needs roughly 600mm of carcass opening once you allow clearance, not exactly 596mm, and a fridge that's deeper than the worktop run will stick out past the cabinet fronts next to it. If a fridge or oven door swings the wrong way for the space beside it, or can't open past 90 degrees next to an island, you want to know that during the measure, not on delivery day with the appliance already unboxed.

11Flag anything awkward on the sketch, not just in your head

Boxed-in soil pipes, a chimney breast that interrupts a run, a meter cupboard, a radiator that can't move, a sloped ceiling under stairs, these all need their own measurements and their own note on the sketch, with distances from a fixed corner. It's tempting to remember these details rather than write them down because they feel obvious in the moment. They stop being obvious a week later when you're drawing the cutting list from a desk and the kitchen itself isn't in front of you anymore.

12Cross-check the whole room before you trust any of it

Once you've got every wall, add diagonals across the overall room shape where you can, corner to corner, and compare that to what a scaled sketch of your numbers would predict. If the diagonal is noticeably off from what the individual wall lengths suggest, you've got a measurement error hiding somewhere in the room, and it's far cheaper to find it now with a tape measure in your hand than later with a jigsaw and an apologetic phone call.

• Steel tape used throughout, not cloth or fibreglass
• Every wall measured at worktop height, to the nearest millimetre
• Opening segments added up and checked against the overall wall length
• Every corner checked for square with the 3-4-5 method
• Walls checked for plumb, not just corners for square
• Floor checked for level in both directions, highest point noted
• Ceiling height checked at multiple points, lowest one used
• Utility points measured from a fixed corner, not estimated
• Appliance widths and door swing recorded, not just the gap
• Diagonals cross-checked against the sketch before anything's finalised