Kitchen Unit and Cabinet Run Calculator

A corner puts a worktop joint there and takes a worktop depth off the later run's units, because they start at the front of the earlier run's worktop. The later run's worktop is a depth shorter too at a butt joint, but not at a 45 degree mitre, where both pieces run into the corner — the corner joint field says which. Runs split by a freestanding cooker, a range or a tall fridge-freezer are separate runs: the worktop, plinth and units stop at it.

Measure at worktop height, from wall to wall or from the wall to where the run stops. Enter the run that holds the appliance spaces as run 1: they are taken off this run. For an L or a U, measure each run along its own wall right into the corner; the page takes off the overlap itself.

Tools needed: Tape measure

In an L or a U this is the run that meets run 1 at the corner, measured right into the corner. In a galley it is the opposite side. When the two meet, its units start at the front of run 1's worktop, and so does its worktop at a butt joint; at a mitre its worktop runs into the corner.

In a U it meets run 2 at the second corner and is measured into that corner. In an L it stands apart: the other side of a cooker, a range or a tall unit, or a separate wall.

No unit goes in these spaces, but the worktop and the plinth run across them, because an integrated appliance takes a door and a plinth that match the units. Take each width from the appliance's installation instructions, which give the opening it needs — often a little more than its nominal width. A sink sits in a sink unit of its own, so it is not a space here.

A freestanding dishwasher or washing machine slid under the worktop, as most US dishwashers are, has its own front and kick plate. The worktop runs across it; no unit or plinth does. Freestanding cookers, ranges and tall fridge-freezers are full height: split the run at them and enter the two sides as separate runs.

Units either side of a dishwasher are two stretches, and each is filled with its own units and its own filler, which can change both the count and the fillers from filling them as one length. The page treats the appliance spaces as one block: if they are apart, measure to the first, and the rest of run 1's units are the other stretch. A figure at or beyond the length of run 1's units means the spaces are at the far end.

Measure along the wall, into the corner where the run turns one, and take off the hood, a window and any open shelving. Where the hood or a window splits the row, say where in the next field, so each stretch is filled with its own units and filler. Zero where there are none.

The stretches either side of a hood are two rows of units, each filled with its own widths and its own filler: two 1.4 m (4 ft 7 in) stretches of metric units take three units each, where one 2.8 m (9 ft 2 in) row would take five in all. Only one break is taken; zero, or a figure at or beyond the wall-unit length, fills the row in one piece.

Where run 1 and run 2 meet at a corner and both have wall units, run 2's wall units start at the front of run 1's, so the page takes a wall-unit depth off this length.

In a U, run 3's wall units start at the front of run 2's where both have them, and the page takes a wall-unit depth off this length.

Each run is filled with as many units of this width as fit, then one or two of the other standard widths make up the rest. Where units are made to metric sizes the widths run from 200 to 1000 mm, with 600 mm the usual module; US cabinets run from 9 to 48 in in 3 in steps, with 24 in common. A 24 in cabinet is 609.6 mm, not 600 mm, so switching the measurement system switches the product and can change the count. The same main width is used for the wall units.

Whatever the units do not fill is closed with a filler strip cut to width. A leftover wider than this makes the page use a different unit instead. US cabinet makers sell fillers 3 in and 6 in (76 and 152 mm) wide. Where a door meets a wall it needs a filler anyway so it can open past the wall — one US maker asks for at least 1 in (25 mm) — even when the units fill the run exactly.

It is taken off the later run's units at each corner, because they start at the front edge of the earlier run's worktop, and off the later run's worktop at a butt joint. It is also the plinth's return at an open end, where the plinth turns back along the side of the end unit, as the supplier method this page follows allows.

Metric wall carcasses are commonly 300 mm deep before the door, and US wall cabinets 12 in (305 mm). This depth is taken off the later wall run at each corner, and is the cornice or pelmet return at each open end — a little shorter than the 400 mm (16 in) nominal return one supplier adds, so round the order up if the profile projects far.

A run between two walls has none. A run that stops in the room — a peninsula, or the end of an L short of the door — has one at that end. Count every run's ends across the kitchen.

Wall units either side of a cooker hood have an exposed end each side of it, and a row that stops short of a wall or a window has one there. An end against a wall or a tall unit is not open.

Laminate worktops sold in metric sizes come in 3.0, 3.6 and 4.1 m lengths at 600 mm deep; US post-form laminate counters in 8, 10 and 12 ft. Stone and solid surfaces are made to a template of the finished units instead, so this count does not apply to them. A longer length can save a joint: the page puts one wherever a run outgrows a length.

A factory end is rarely a finished end, and a piece that meets a wall is scribed to it. The allowance is added to every piece, so a run that exactly matches a stock length needs a longer length or a joint. Set it to zero to count the lengths with nothing to spare.

At a butt joint or a masons mitre one worktop runs into the corner and the other stops against its front edge, so the later piece is a worktop depth shorter. US post-form counters meet at a 45 degree mitre, made at the factory and drawn together with miter bolts: each piece's back edge runs into the corner, so both are cut at their full wall length, and no two mitred pieces are cut from one length. The joint does not change the units, which start at the front of the earlier run's worktop either way.

One UK kitchen supplier lists plinth in 2600, 2750 and 3000 mm lengths and cornice and pelmet in 2700 and 3000 mm; one US cabinet maker lists its toe kick and crown mouldings at 94 in. Choose another length if yours differs; all three are counted in the same length.

Metric flat-pack and rigid carcasses usually stand on adjustable legs with the plinth clipped to them; US face-frame cabinets usually have the toe kick built into the box and a thin toe kick skin across it. The page counts four legs a unit; the carcass maker may want more under units wider than 600 mm (24 in).

Choose the item you are adding to a project or ordering, and the headline becomes that count. The breakdown always shows every item for the whole kitchen.