A worktop at the wrong height is the most tolerated fault in a kitchen, and it is tolerated because nobody notices it until they have used someone else’s. The rule is that the surface should sit below the elbow, by about fifteen centimetres for general work and by less for work that needs pressure from above. Since elbow height tracks stature, that means the worktop is a function of who uses the kitchen — which is why the standard 900 millimetres suits some people perfectly and gives others a bad back for twenty years. This works it out from stature and from the task, and then gives you the wall units and the plinth that follow from it.
User, task and units
The worktop is set by the elbow, and the elbow is set by the person.
Result
Half your height, plus something
Elbow height tracks stature closely enough that a single rule works: the worktop goes at roughly half the user's height, adjusted for what the surface is for. For a 1.68 m person that is 84 centimetres, and general preparation wants another five, so 89 — which is why 90 is the standard and why it suits a surprising number of people reasonably well.
The adjustment is the part that gets skipped, and it is worth making because the range is real. Work that needs downward pressure — kneading dough, rolling pastry, chopping with a heavy knife — wants a lower surface, because the force comes from the shoulder and a high surface shortens the lever. Work that needs the eye close — fine slicing, decorating, piping — wants a higher one, because it brings the work up towards the face instead of making the back bend down towards it.
Why one kitchen often needs two heights
The honest answer in most kitchens is that no single height is right for everything, and the usual compromise — one height everywhere — is a compromise nobody chose. A lower section for pastry and heavy work, and a higher one at the hob so you can see into the pan without stooping, costs nothing extra in a made-to-measure carcass run and changes how the kitchen feels to use.
The sink is the special case. A sink is a hole, so the hands work below the surface, and the standard advice is to raise the section containing it by about five centimetres so that the base of the bowl is roughly where a normal worktop would be. Undermounted sinks make this easier, because the rim does not eat into the working height.
A base unit is not the worktop height. It is the worktop height less the worktop and less the plinth — typically 150 millimetres of plinth and 40 of worktop, so 710 mm of carcass under an 890 mm surface.
Get that wrong and the units are either floating on a tall plinth or sitting on the floor with no toe kick, and neither can be fixed once the worktop is on.
Wall units, and what you can actually reach
Wall units hang with their bottom edge about 55 centimetres above the worktop, which clears a kettle, a stand mixer and most small appliances, and leaves a splashback of the same height behind. Higher than that and the shelf is out of reach for anything used daily; lower and the work surface underneath stops being usable for anything tall.
The real limit is the reach. A comfortable standing reach is roughly twenty percent more than the person's height, so about two metres for someone of 1.68 — and a wall unit with its bottom edge at 1.44 and a height of 0.7 has its top at 2.14, which is above it. That does not mean the unit is wrong; it means the top shelf of a tall unit is for things used once a year, and the everyday things go on the bottom two.
| Element | Typical | Set by | Note |
|---|---|---|---|
| Worktop | 0.85 to 0.95 m | User and task | Half the height, adjusted |
| Base carcass | 0.70 m | Worktop less top and plinth | Standard is 720 mm |
| Plinth | 0.15 m | Toe kick | Recessed 50 to 70 mm |
| Splashback | 0.55 m | Worktop to wall units | Sometimes full height |
| Wall unit, bottom | 1.44 m | Worktop plus 0.55 | Clears a kettle |
| Tall unit, top | 2.14 m | Unit height | Above comfortable reach |
A worked example
- The surfaceHalf of 1.68 m is 0.84, plus 0.05 for general work: 0.89 m.
- What to buyThe nearest standard carcass is 0.90 m — the usual figure, and right for this user.
- Base unitsLess 40 mm of worktop and a 150 mm plinth, the carcass is 0.70 m.
- Wall unitsBottom edge at 0.89 + 0.55 = 1.44 m, top at 2.14 m.
- ReachComfortable reach is 2.02 m, so the top 120 mm of the wall unit is for things used rarely.
Eighty-nine against ninety is one centimetre, and it is the whole difference between a kitchen that is right for the person using it and one that is right on average. Averaging is not the same as fitting.
Fitting it
Set the base units level first, in the run, before anything goes on top. Shim rather than force: a run of units on an uneven floor that has been screwed together level will hold a worktop in a permanent twist, and the twist shows at every joint and every door gap.
Hang wall units on a batten or a rail rather than straight through the back, because the load then goes into the rail and into several fixings rather than into two screws in plasterboard. And fix into the studs where you can find them — a wall unit full of plates is a genuinely heavy thing hanging over a work surface.
Then the two figures that sit either side: the shelf spacing figure works out what goes inside the units and how much of the volume is actually usable, and the wall area figure sizes the splashback and the decorating behind it. If the kitchen is part of a bigger job, the renovation timeline is where the ordering of the trades gets planned.
Do
- Set the worktop from the user's height and the task, not from habit.
- Consider two heights: lower for heavy work, higher at the hob.
- Subtract the worktop and the plinth to get the carcass.
- Hang wall units on a rail, into studs where possible.
- Level the base run before the worktop goes on.
Avoid
- Fitting the standard 900 mm without checking who uses it.
- Forgetting the plinth and ending up with the wrong carcass height.
- One height everywhere when the kitchen does two different jobs.
- Hanging units through the back into plasterboard.
- Screwing a twisted run level and expecting the worktop to sit flat.
Where the numbers stop being true
The half-your-height rule is a population average with a lot of scatter. Arm length, torso length and leg length vary independently of stature, and two people of exactly the same height can want worktops several centimetres apart. The reliable test is not arithmetic: stand with the forearm horizontal and measure to the underside of the elbow, then subtract.
Nothing here covers a seated user, a wheelchair user, or a kitchen that has to work for both. A seated worktop wants a clear knee recess under it rather than a cupboard, and a height set by the chair rather than by the person's standing stature — which usually means a section at 750 millimetres with the plinth omitted.
And the reach figure is for an unobstructed standing reach to a shelf you can see. Reaching over a worktop that has things on it, reaching into the back of a deep corner unit, and reaching up while holding something heavy are all shorter, and they are the reaches that cause the accidents.
How the figures are produced
The worktop is half the user's height plus the offset for the chosen task. That is compared with four standard carcass heights and the nearest one is picked. The base carcass is the worktop less the worktop thickness and the plinth. Wall units have their bottom edge 55 centimetres above the worktop, their top is that plus the unit height, and a comfortable reach is taken as twenty percent more than the user's stature.
Questions people ask
What height should a kitchen worktop be?
About half the main user's height plus five centimetres. For a 1.68 m person that is 89 cm, so the standard 90 cm carcass.
Is 90 cm right for everyone?
No. It suits an average-height user doing general preparation. Shorter or taller users, or heavy or fine work, want something different.
How high do wall units go?
Bottom edge about 55 cm above the worktop — around 1.44 m from the floor on a standard worktop.
Can I reach the top shelf?
Often not comfortably. A comfortable standing reach is about 1.2 times your height, and a tall wall unit exceeds it.
Should the sink be at a different height?
Slightly higher, yes — about five centimetres — because the hands work below the rim rather than on the surface.
What about a seated user?
Lower, and with a clear knee recess instead of a cupboard. Usually around 75 cm, set by the chair.