Countertop overhang

The standard overhang

Base cabinets are 24 in deep, and the countertop on them is a little deeper, so its front edge sits past the cabinet doors:

Caesarstone gives the 1½ in directly; the other two are our arithmetic from their counter depths. Doors and drawer fronts are about ¾ in thick, so a 1½ in lip ends about ¾ in past them.

The lip covers the doors and drawer fronts and keeps drips off them. More on the depths on standard counter depth.

Overhang for seating

Where stools or chairs go, the top has to reach far enough for knees. NKBA’s knee space depends on the height of the top, since people sit more upright at a bar:

Knee space from NKBA; the depth is the cabinet, a 1½ in lip on the work side and the knee space (our arithmetic). NKBA also gives each person 24 in of counter length.

Stool spacing and the room behind the stools are on kitchen island seating, and the whole island on kitchen island dimensions. A peninsula takes the same overhangs; see kitchen peninsula.

When an overhang needs support

Stone and quartz are heavy and brittle, so the makers set how far a top may reach on its own. Past that it needs brackets or corbels under it, and past a second limit, legs, panels or a full support. MSI gives a table for its Q quartz on 24 in cabinets:

MSI’s Q Quartz installation guidelines (the web page, and its PDF of August 2026), which it calls a general guideline, written for fabricators. The subtop column leaves 20 to 24 in unassigned; ask MSI or your fabricator there. MSI’s August 2026 blog on quartz thickness rounds the first column to “up to” 16 in and “not exceed” 8 in; the installation guide says less than.

Cambria’s rules go by thickness, with a cap set by depth:

• Corbels once an overhang is more than 12 in on 2 cm or 15 in on 3 cm: at most 36 in apart, each reaching at least three quarters of the overhang and fixed to studs or another load-bearing structure.
• A full substrate and legs at most 36 in apart once it is more than 18 in on 2 cm or 24 in on 3 cm.
• A third of the depth at most, corbels or not. Cambria’s installation requirements (SOP 9.3.3) measure it against the countertop, drawn as two thirds on the cabinets and one third overhanging; its technical guideline (reviewed May 2024) says a third of the base cabinet’s depth. On a single run of 24 in cabinets that allows about 12 in by the first wording and 8 in by the second, so there this rule, not the corbel limit, sets the longest overhang. A longer one needs a deeper base, or a support design the fabricator confirms with Cambria.
• Support within 3 in of any cutout, such as a sink or cooktop in the island, and under every seam, including seams in the overhang.
• No sag: the cabinets or frame must carry the top without deflection and be flat to within ⅛ in over 8 ft.

What that means for the three seating overhangs on 24 in cabinets:

• A 12 in bar overhang needs no added support in MSI 3 cm, and brackets in MSI 2 cm, even on a subtop, whose limit is less than 12 in. It is at Cambria’s corbel limit for 2 cm, within its one-third rule by the SOP’s wording but past the guideline’s 8 in.
• A 15 in counter-height overhang is under MSI’s 16 in for 3 cm and needs brackets in 2 cm. For Cambria it is past a third of the depth by either wording on a single 24 in run (a third of a 40½ in top is 13½ in), so it needs a deeper base or a support design your fabricator confirms.
• An 18 in table-height overhang needs brackets in MSI 3 cm and on a 2 cm subtop, and legs, columns or panels in plain 2 cm. Cambria asks for corbels in both thicknesses, and on a single 24 in run it is past a third of the depth too.
• Brackets from the cabinet maker have their own limits: Hampton Bay’s metal corbel for its frameless line is rated for overhangs up to 12 in, and its guide says to follow the countertop maker’s specs.

These are the makers’ rules for their own tops, written for fabricators and installers. Other brands, natural stone slabs and other materials have their own, and the base under the top, cutouts, seams and a frame that doesn’t sag matter as much as the span. The fabricator who templates your top decides what goes under it: ask them to confirm the overhang, the base and the supports before the top is cut. How thick each material is comes on countertop thickness.

How to measure an overhang

1. From the face of the cabinet box, not the door: the box is what carries the top. Hold a straight edge against the box and measure out to the front edge of the counter.
2. On a seating side, measure from the back or side panel of the cabinets to the edge. That is the knee space.
3. Check the thickness at the edge (2 cm or 3 cm on stone and quartz), and whether the top sits on a subtop, since the support limits depend on it.
4. Measure the cabinet run behind it, and how deep the base under the top is. Brackets and legs go every 24 to 36 in, depending on the maker, so the run sets how many you need; Cambria also limits an overhang by the depth.

Questions people ask