How to size kitchen countertops
Measure the cutout, not the existing unit
Standard countertop dimensions: 25.5″ deep (1.5″ overhang past 24″ cabinets), 36″ tall above floor (matches 34.5″ cabinet + 1.5″ counter thickness). Stone (granite, quartz) is sold in slabs — typical slab is 60″×110″, so any seam-free run longer than ~10 ft is impossible without joining slabs.
Plumbing and electrical reduce usable depth
Supply lines, drains, vent ducts, and electrical run in the back 3–4″ of most cabinets. The catalog dimension assumes those connections sit flush against the back wall. If a previous installation routed lines along the side, the new unit may not fit even though the cutout looks correct. Pull the existing unit before ordering to confirm.
Standard vs. compact sizing
Counter heights: 36″ standard, 42″ bar, 30″ ADA / desk-height. Counter overhang: 1.5″ standard front, 12″ for unsupported breakfast-bar seating, 15″ for stools at full counter height.
Common mistakes
- Assuming all "standard" units in the same category are interchangeable. Cabinet height varies by 1–2″ between brands.
- Adding new flooring under the existing unit; the new layer traps the unit under the counter.
- Ignoring door swing or pull-out clearance in front of the unit.
- Mixing US and EU standards. EU appliances are sized in centimetres (60 cm ≈ 23.6″), not 24″.