Glass Weight Calculator 2.5 kg per m² per mm
Enter the pane dimensions, thickness and material. Metric in millimetres for kilograms, imperial in inches for pounds.
One Number to Remember
Single Pane Only
How much does a sheet of glass weigh?
At a Glance
Multiply area by thickness by density: weight = length × width × thickness × 2,500 kg/m³ for ordinary float glass. That works out to a rule worth memorising — 2.5 kg per square metre for every millimetre of thickness. A 1 m × 1 m pane of 6 mm glass weighs 15 kg.
Toughened glass, heat-strengthened glass and ordinary annealed float glass all weigh exactly the same. Tempering changes the stress profile inside the sheet, not its composition — so a 6 mm toughened pane is no heavier than a 6 mm annealed one.
What does change the weight is a genuinely different material:
| Material | Density (kg/m³) | Per m², 6 mm |
|---|---|---|
| Float / toughened glass | 2,500 | 15.0 kg |
| Laminated glass | 2,500 | 15.0 kg |
| Borosilicate | 2,230 | 13.4 kg |
| Polycarbonate | 1,200 | 7.2 kg |
| Acrylic (PMMA) | 1,190 | 7.1 kg |
Acrylic and polycarbonate weigh less than half what glass does at the same thickness, which is often the deciding factor for overhead glazing or anything that has to be carried up a ladder.
weight = length × width × thickness × densityThese are the values the calculator loads by default.
Work out the area
1,000 × 1,000 mm = 1.0 m².
Turn it into a volume
1.0 m² × 0.006 m = 0.006 m³ of glass.
Apply the density
0.006 × 2,500 = 15 kg.
Check it against the rule of thumb
2.5 kg/m²/mm × 1 m² × 6 mm = 15 kg. Same answer — which is why that rule is worth remembering when you are standing in a merchant's yard without a calculator.
Glass gets heavy faster than people expect, and the number has practical consequences.
Two-person lifts start early. A 2 m × 1 m pane of 6 mm glass is 30 kg — awkward rather than heavy. The same pane in 10 mm is 50 kg, which is a two-person lift with suction cups, not a hero move.
Fixings carry the whole load. Shelf brackets, hinges and clamps are rated by weight; a 1 m × 0.3 m shelf in 10 mm glass is 7.5 kg before anything is put on it.
Double glazing is not double. A sealed unit made of 4 mm and 4 mm panes weighs about 20 kg/m² — the two panes plus a small allowance for spacer and sealant. Calculate each pane and add them.
For other materials, Density Calculator works the general case and Pipe Weight Calculator handles hollow sections.
Nominal thickness and a single pane
Glass is sold by nominal thickness, and the real sheet is allowed to differ: EN 572 permits roughly ±0.2 mm on 4-6 mm float glass. On a large pane that is a percent or two either way.
Laminated glass is treated here as solid glass at 2,500 kg/m³. The PVB interlayer is slightly lighter, so a laminated pane comes out a touch heavy in this calculation — typically under 1 % for a standard 0.38 mm interlayer, more for thick acoustic or security laminates. Frames, seals, coatings and fittings are not included at all.