Glass weight calculator
Enter panel size and thickness to get the weight in kilograms — for annealed, toughened, laminated and double-glazed (DGU) glass. Useful for planning lifting, hinges, channels and transport.
Basis: 2.5 kg per m² per mm (soda-lime glass, 2,500 kg/m³). Actual weight varies slightly with holes, cutouts and edge work — confirm with your fabricator for lifting and hardware decisions.
The formula
Weight (kg) = area (m²) × thickness (mm) × 2.5. Soda-lime glass — which is what windows, partitions, shower doors and table tops are made of — has a density of about 2,500 kg/m³, so every millimetre of thickness adds 2.5 kg per square metre. Toughening does not change the weight; laminated glass uses its nominal combined thickness; a DGU weighs the sum of its two panes (the air gap adds nothing).
Worked example: a 1200mm × 2100mm shower door in 8mm toughened glass = 1.2 × 2.1 = 2.52 m² × 8 × 2.5 = 50.4 kg. That is a two-person lift, and the hinge set must be rated above it.
Glass weight chart (kg per m² and per sq ft)
| Thickness | Weight per m² | Weight per sq ft |
|---|---|---|
| 4 mm | 10.0 kg | 0.93 kg |
| 5 mm | 12.5 kg | 1.16 kg |
| 6 mm | 15.0 kg | 1.39 kg |
| 8 mm | 20.0 kg | 1.86 kg |
| 10 mm | 25.0 kg | 2.32 kg |
| 12 mm | 30.0 kg | 2.79 kg |
| 15 mm | 37.5 kg | 3.48 kg |
| 19 mm | 47.5 kg | 4.41 kg |
Frequently asked questions
How do you calculate the weight of glass?
Multiply the area in square metres by the thickness in millimetres by 2.5. Example: a 1.2m × 2.1m panel of 8mm glass weighs 1.2 × 2.1 × 8 × 2.5 = 50.4 kg. The 2.5 factor comes from the density of soda-lime glass (2,500 kg/m³).
Does toughened glass weigh more than normal glass?
No. Toughening changes the stress profile of the glass, not its density — a toughened panel weighs the same as an annealed panel of the same size and thickness.
How much does 12mm toughened glass weigh per square foot?
12mm glass weighs about 30 kg per square metre, which is roughly 2.8 kg per square foot. A typical 4ft × 8ft (32 sq ft) sheet of 12mm glass weighs around 90 kg.
How is laminated glass weight calculated?
Use the nominal laminated thickness (e.g. 6.38mm for 3+3 with a 0.38mm PVB interlayer) in the same formula. The polymer interlayer is slightly lighter than glass, but the difference is under 1% — negligible for handling and hardware decisions.
Why does glass weight matter?
Weight decides how many installers a panel needs, whether it can be carried up stairs or needs lifting equipment, and which hinges, patch fittings, sliding channels and wall anchors are rated for it. Most shower-door hinges, for example, are rated for 40–60 kg per pair.
Need the glass itself?
Tell us the size and type — we'll connect you with verified glass suppliers near you for a free, no-obligation quote.
Request a free quotation →Also see: glass thickness guide, price estimator, standard sheet sizes.