Glass weight

How heavy is a window pane, a glass tabletop or a shower panel? This calculator turns sheet size and thickness into weight so you can plan delivery, choose hinges and supports and organise a safe installation.

How the calculation works

The calculation uses the density of standard float (soda-lime) glass, 2,500 kg/m³, the value given in the European standard EN 572-1 and widely used in glazing design. That gives a handy rule: one square meter of glass 1 mm thick weighs 2.5 kg.

Formula: sheet area (width in meters × height in meters) × thickness in millimeters × 2.5 = weight of one sheet in kg, then multiplied by the number of sheets. Enter width and height in millimeters (10–6,000 mm) and thickness in millimeters in 0.5 mm steps; 1/4″ glass is about 6 mm, 3/8″ about 10 mm.

You get the total weight, the area of one sheet in m² and the weight of a single sheet. Tempered glass has the same density as annealed glass, so the result applies to it as well.

Worked example

One sheet of 1,000 × 1,000 mm at 4 mm (the defaults): area 1 m², weight 1 × 4 × 2.5 = 10 kg (about 22 lb). A 1,200 × 1,500 mm window pane at 6 mm weighs 1.8 m² × 6 × 2.5 = 27 kg, so two of them come to 54 kg. As a rule of thumb, 6 mm glass is roughly 3.1 lb per square foot.

Things to keep in mind

• For insulated glass units, count the glass only: a 4-16-4 unit has two 4 mm panes, about 20 kg per m². The spacer and sealant add a little extra.
• Laminated glass weighs almost the same as its glass plies; the PVB interlayer is thin and lighter than glass, so enter the combined glass thickness.
• Actual thickness may vary slightly within manufacturing tolerances, so add a safety margin when sizing brackets or supports.
• Carry large sheets upright with suction lifters and at least two people; glass laid flat without full support can crack under its own weight.
• Patterned, wired or special glass may have a different density — check the manufacturer’s data sheet.