Guide · Specification
18 mm vs 20 mm quartz
Two millimetres of difference, and almost all of it shows up in three places: the bridge of stone in front of a sink cutout, an unsupported overhang, and how well a joint holds.
The short answer
20 mm is the standard for kitchen countertops in India and it is the only thickness we stock. 18 mm is not a bad material, but the saving is small and it takes away margin exactly where a countertop is most likely to fail: at overhangs, at breakfast bars, and at the strip of stone in front of a sink cutout.
What the numbers mean
| Thickness | Also written | Typically used for |
|---|---|---|
| 18 mm | 1.8 cm | Budget and some imported lines. Wall cladding, vanity tops, fully supported platforms. |
| 20 mm | 2 cm | The standard for kitchen countertops. What we stock, in all 34 designs. |
| 30 mm | 3 cm | Commercial counters, large unsupported islands, heavy-use worktops. |
The difference between 18 and 20 is two millimetres — about the thickness of a one rupee coin. It sounds trivial, and on a fully supported run it nearly is. It stops being trivial the moment the stone has to hold itself up.
Where the two millimetres matter
Sink cutouts
A cutout leaves a narrow bridge of stone between the opening and the front edge of the counter, usually 60 to 90 mm wide. That bridge carries the whole front rail of the platform and takes every knock from a vessel going into the sink. It is the single most common place a quartz counter cracks, and it is where the thicker section earns its money. Undermount sinks make it worse, because the sink hangs from the stone.
Overhangs and breakfast bars
Any stone cantilevered past its support — a 250 mm seating overhang, a bar top, the nose of an island — is a bending problem. 20 mm can span noticeably more before it needs steel or a ply subframe underneath. In 18 mm the same detail needs bracing that adds cost, which erodes the saving that led you to 18 mm.
Joints
A butt joint between two pieces is bonded with colour-matched resin and relies on the thickness of the edges being glued. A thicker edge gives more area for the bond and a joint less likely to open up as the base settles.
Handling
Thinner slabs are more fragile before installation, not after. Most 18 mm breakage happens during transport, lifting up a stairwell, or tilting a long run into place in a tight kitchen.
The one real advantage of 18 mm: weight. A jumbo 20 mm slab weighs roughly 280 kg. In 18 mm it is about 250 kg. On a fourth floor with no lift, or on a lightweight modular carcass rather than masonry, that difference is worth considering — and it is the only situation where we would suggest sourcing 18 mm.
What the thickness looks like
From above, nothing. The only place thickness is visible is the front edge, and there you have choices that matter more than the two millimetres:
| Edge | Charge | Effect |
|---|---|---|
| Pencil nose | Included | A slight round on the top arris. Reads as exactly what it is — 20 mm. |
| Bull nose | ₹150 / Rft | Fully rounded edge. Softer, and safer at a corner. Still 20 mm. |
| Mitred | ₹300 / Rft | A strip bonded under the edge at 45°, so the counter reads 40 mm or more with the veining running round the corner. |
If you want the substantial look of a thick slab, a mitred edge on 20 mm gets you there for less than buying 30 mm stone, and weighs the same as the 20 mm you started with. Rft is running feet of visible finished edge, not slab perimeter.
What we supply
20 mm, in two slab sizes:
| Size | Dimensions | Area | Thickness |
|---|---|---|---|
| Regular | 322 × 147 cm | 51 sq ft | 20 mm |
| Jumbo | 321 × 163 cm | 56.32 sq ft | 20 mm |
Rates run ₹488 to ₹1030 per square foot depending on series, with fabrication and installation at ₹12,000 per slab. See the rate card for the full breakdown, or the FAQs before you ask for a quote.
Common questions
What thickness quartz is standard for a kitchen countertop in India?
20 mm, written as 2 cm. Every slab we stock is 20 mm. 18 mm appears in some imported and lower-cost lines, and 30 mm is made for commercial work and heavy-duty islands.
Is 18 mm quartz strong enough for a kitchen?
On a fully supported base — a masonry platform or a continuous plywood deck — 18 mm works. The weakness shows on unsupported spans: an overhang, a breakfast bar, or the narrow bridge of stone in front of a sink cutout, where 18 mm deflects more and is likelier to crack.
Does 18 mm cost much less than 20 mm?
About ten per cent less on the stone, because there is ten per cent less material. Fabrication and installation are identical. On a one-slab kitchen the saving is a few thousand rupees, which is why most buyers choose 20 mm.
How do you make a 20 mm countertop look thicker?
A mitred edge. A strip of the same slab is cut at 45 degrees and bonded to the underside, so the visible edge reads as 40 mm or more with continuous veining around the corner. We charge ₹300 per running foot for it.
What thickness do you stock?
20 mm only, in both regular 322 × 147 cm and jumbo 321 × 163 cm slabs, across all 34 designs.
Not sure which detail you want?
Come and put your hand on a pencil nose, a bull nose and a mitred edge in Maduravoyal. It takes a minute and settles the question.