Glass Thickness Guide: 4mm to 12mm and Where Each Is Used
Household glass runs from 4mm to 12mm, and each thickness has its home. 4mm and 5mm suit small windows, cabinet doors, and picture frames. 6mm is the everyday all-rounder for medium windows, shelves, and framed shower screens. 8mm covers larger windows, splashbacks, and semi-frameless screens. 10mm is the standard for frameless shower screens and lighter balustrades. 12mm is the heavy-duty choice for frameless balustrades and large unsupported panels. Thicker glass is stronger and spans further, but costs more per square metre and weighs more, so the correct thickness is matched to the span and the job, not maximised.
Key takeaways
- 4mm to 5mm: small windows, cabinet doors, picture frames.
- 6mm: the all-rounder for medium windows, glass shelves, and framed shower screens.
- 8mm: larger windows, glass splashbacks, semi-frameless shower screens.
- 10mm: frameless shower screens and lighter glass balustrades.
- 12mm: frameless balustrades and large unsupported panels; thicker is stronger but heavier and dearer.
Thin glass: 4mm to 6mm
At the thin end, 4mm and 5mm glass is used where the pane is small and well supported: cabinet and cupboard doors, picture frames, small fixed windows, and the like. It is light and inexpensive, but it flexes over any real span, so it is not used for large panes or anything freestanding.
6mm is the workhorse thickness. It covers medium windows, most glass shelves, framed shower screens where the frame carries the load, and back-painted splashbacks. It has enough rigidity for everyday panels while staying reasonably priced and easy to handle, which is why it turns up more than any other thickness in a typical Adelaide home.
Choosing between these comes down to span and support. A pane held on all edges in a frame can be thinner than the same-size pane standing free, because the frame does the structural work.
Thick glass: 8mm to 12mm
8mm steps up to larger windows, bigger splashbacks, and semi-frameless shower screens where the glass carries more of its own load. It is noticeably heavier and stiffer than 6mm and bridges the gap between framed and frameless work.
10mm is the standard for frameless shower screens and lighter glass balustrades, because a frameless panel has no frame to support it and must be rigid enough to stand on its hinges or base channel alone. 12mm is the heavy-duty choice for frameless balustrades, large unsupported panels, and pool fencing where the span and the fall risk demand maximum stiffness.
All of these thicker panels in these positions are toughened, because they are safety-glass locations as well as structural ones. Thickness and toughening work together: the thickness gives rigidity, the toughening gives the safe breakage and added strength.
Thickness versus strength and price
Thicker glass is stronger and spans further before it flexes, but 2 costs come with it: the price per square metre rises with thickness, and the weight climbs, which affects hinges, fixings, and handling. A 12mm balustrade panel is a heavy, expensive piece compared with a 6mm shelf of the same area.
That is why the correct approach is to match thickness to the job rather than reach for the thickest option. Oversizing wastes money and loads the fixings unnecessarily; undersizing risks flex, sagging shelves, or breakage. The span, the support, and whether the panel is freestanding all feed into the right number.
Toughening changes the equation too: a toughened pane is far stronger than plain float of the same thickness, so a safety position may be met with a given thickness in toughened form. We connect you with vetted local specialists who spec the right thickness and grade for each panel so you can compare 3 free quotes with confidence.
Ready to get real numbers? Compare 3 free quotes from vetted Adelaide specialists for glass splashbacks.
Frequently asked questions
A short, well-supported shelf can be 6mm, while a longer shelf or one carrying heavier items steps up to 8mm or 10mm to avoid sagging. Span and load set the thickness, so a wide unsupported shelf needs thicker glass than a narrow one.
No. Thicker glass is stronger and spans further, but it costs more per square metre and weighs more, which loads hinges and fixings. The right thickness is matched to the span, support, and use of each panel rather than maximised.
Frameless shower screens are typically 10mm toughened glass, because the panel has no frame and must stand rigidly on its own hinges and clamps. Semi-frameless screens can use 8mm, and framed screens can go thinner since the frame provides support.