The right glass thickness depends on what the glass is for. As a guide, shelves are 6, 8 or 10 mm depending on the span, shower glass is 8 or 10 mm, splashbacks are 6 mm, mirrors are 4 or 6 mm and table tops are 10 or 12 mm. Our glass thickness tool gives the pick for your job and says whether it is toughened.
What thickness does the thickness tool suggest?
These are the trade-standard picks the thickness tool gives for each use:
| Use | Suggested thickness | Notes |
|---|---|---|
| Shelf, span up to 500 mm | 6 mm toughened | Span is the distance between supports |
| Shelf, span 500 to 800 mm | 8 mm toughened | |
| Shelf, span over 800 mm | 10 mm toughened | Check the sag calculator too |
| Table top | 10 mm toughened | The standard for full glass table tops |
| Table protector | 6 mm toughened | Protects an existing surface |
| Splashback | 6 mm toughened | Required behind hobs |
| Shower screen | 8 mm toughened | 10 mm for frameless |
| Balustrade | 10 mm toughened minimum | Needs a site-specific check, often 12 mm or laminated |
| Internal door | 10 mm toughened | For frameless internal doors |
| Single-glazed window | 4 mm float | Safety glass if in a critical location |
| Mirror | 4 mm up to about 1 m; 6 mm larger | 6 mm for large or frameless mirrors |
| Greenhouse | 4 mm toughened |
The tool's own disclaimer applies: this is guidance for planning, not a structural calculation. Balustrades, floors, overhead glazing and anything load-bearing need a site-specific design check. Confirm with your building inspector or engineer before you order.
Which thicknesses can I order for each product?
The configurator only offers the thicknesses each product allows:
- Shower and bath glass: 8 or 10 mm, always toughened. Satin and fluted glass come in 10 mm only. A hinged door must be 8 or 10 mm, because the hinge has to grip the glass.
- Splashback: 6 mm, always toughened.
- Mirror: 4 or 6 mm, not toughened.
- Shelf: 6, 8 or 10 mm. Toughening is optional, and every glass shelf we cut is toughened unless you ask otherwise.
- Table top: 10 or 12 mm, always toughened.
Why toughening matters is covered in toughened, laminated and annealed glass.
How heavy will my glass be?
Every millimetre of thickness weighs 2.5 kg per square metre. So a square metre of 10 mm glass weighs 25 kg, and a square metre of 4 mm weighs 10 kg.
Worked example: a shower panel 900 × 2000 mm in 10 mm glass.
- Area: 0.9 m × 2.0 m = 1.8 m²
- Weight per square metre: 10 mm × 2.5 kg = 25 kg per m²
- Weight: 1.8 m² × 25 kg = 45 kg
The glass weight tool does this for you and shows the workshop's handling band: one person up to 20 kg with no edge over 1500 mm, two people up to 50 kg or any edge up to 2500 mm, and mechanical handling beyond that. Those bands are our workshop's rule for glass, not a universal safe lifting limit. Manual handling should be assessed for the task, the load, the route and the person; see the HSE manual handling guidance.
How much will a glass shelf hold?
The shelf load tool takes the span, depth, thickness and how the shelf is held, and gives the load it carries spread evenly. Read its limits before you rely on it:
- It is a planning guide, not a structural certification, and not a design to BS EN 16612.
- It assumes the load is spread evenly, the edges are clean and polished, and the fixings carry the load.
- A heavy object at the centre, a chipped edge or a weak bracket all reduce what the shelf holds.
- It does not cover a shelf held only along its back edge in a wall channel.
Where the load matters, ask us for a specification and have anything load-bearing checked by an engineer.
When do I need a design check?
You need a site-specific design check for balustrades and barriers, glass floors, overhead glazing and anything load-bearing. Our tools do not replace that check, and their results are not a structural design. Balustrade designs go to a person on our team rather than being priced online; see balustrades.
Where to go next
Check your pick with the glass thickness tool.
Questions we get asked
Is 8 mm or 10 mm better for a shower screen?
8 mm toughened is the wetroom standard and 10 mm suits frameless screens. Satin and fluted glass come in 10 mm only.
How do I work out the weight of a glass panel?
Multiply the area in square metres by the thickness in millimetres, then by 2.5 kg. A 1.8 m² panel of 10 mm glass weighs 45 kg.
Can I use the shelf load result as a structural design?
No. It is a planning guide that assumes an evenly spread load. Ask us for a specification and have anything load-bearing checked by an engineer.