Guide · Clear glass
What thickness glass do I need? 4mm to 19mm explained
Which glass thickness to order for windows, cabinet doors, shelves, table tops and shower screens, with weights and Sydney prices.
Quick answer: 4mm for picture frames and small panes, 5–6mm for most windows and cabinet doors, 8mm for larger shelves, 10mm toughened for frameless shower screens and table tops, 12mm for dining tables and wide spans. Glass weighs about 2.5 kg per m² for every millimetre. A 600 × 900mm clear panel with polished edges is $153.02 in 6mm and $166.16 in 10mm, including delivery in Sydney.
Thickness by use
| Thickness | Typical use | Weight | 600 × 900mm, polished, delivered |
|---|---|---|---|
| 4mm | Picture frames, small window panes, cabinet backs | 10 kg/m² | $153.02 |
| 6mm | Windows, cabinet doors, short shelves | 15 kg/m² | $153.02 |
| 8mm | Larger shelves, protective table covers | 20 kg/m² | $166.16 |
| 10mm | Frameless shower screens, table tops, long shelves | 25 kg/m² | $166.16 |
| 12mm | Dining tables, wide spans, large screens | 30 kg/m² | $175.70 |
Shelves: go by the span
For a shelf supported at both ends with a normal load: up to 400mm between supports, 6mm; 400 to 700mm, 8mm; 700 to 900mm, 10mm; beyond 900mm, 12mm and an extra support. Deep shelves, heavy loads and small pin supports push you one size up. See glass shelf thickness.
Thicker is not safer
Thicker ordinary glass still breaks into sharp shards. Where safety glass is needed, it must be toughened or laminated. See when you need safety glass.
Check the weight before you order
A 2000 × 900mm panel in 12mm weighs about 54 kg. Make sure you can carry it, the fixings can hold it, and it will fit through the door. Glass cannot be trimmed once it is made.
Common questions
What thickness glass do I need for a shelf?
Up to 400mm span, 6mm; 400 to 700mm, 8mm; 700 to 900mm, 10mm; over 900mm, 12mm with an extra support. Go one size up for deep shelves, heavy loads or pin supports.
What thickness is a glass table top?
6–8mm as a protective cover on a solid table. A top that sits on a base by itself is usually 10mm toughened, or 12mm for a large dining table.
What thickness is shower screen glass?
Frameless screens are 10mm toughened. Semi-frameless screens are usually 6–8mm toughened and framed screens 4–6mm toughened.
How heavy is glass?
About 2.5 kg per m² per millimetre: 4mm is about 10 kg/m², 6mm 15 kg/m², 10mm 25 kg/m² and 12mm 30 kg/m².