Glass Weight Calculator: Weight of a Glass Pane, Laminated Glass or Double-Pane Unit

How it works

weight = area × thickness × density × number of panes (+ area × interlayer thickness × 1,070 kg/m³ for laminated) · soda-lime glass ≈ 2,500 kg/m³ = 2.5 kg/m² per mm = 156 lb/ft³ ≈ 13 lb per sq ft per inch

Glass weight is its volume times its density. Ordinary window, mirror, shower and tabletop glass is soda-lime float glass at about 2,500 kg/m³, which makes the handy rule of 2.5 kg per square metre for every millimetre of thickness, or about 13 lb per square foot for every inch (3.25 lb per sq ft for 1/4 in). Tempering does not change the weight, low-iron glass is almost the same, and borosilicate is about 11% lighter. Choose the construction to add up the panes: a laminated sheet is two plies plus a PVB interlayer (about 1,070 kg/m³), and a double- or triple-pane insulated unit is two or three panes, since the gas gap weighs almost nothing. The table shows the weight of your piece at every standard thickness, in inch sizes on the US view and millimetre sizes on the metric view. Unlike the metal weight calculator (steel and other metals) or the glass block calculator (block counts for a wall), this one is for flat glass. Note that US nominal thicknesses are often made slightly thinner (1/4 in glass is usually about 6 mm), so a real pane can weigh a few percent less than the nominal-inch figure; enter the measured thickness if you need precision.

Worked example

A 36 × 48 in pane of 1/4 in float glass has an area of 36 × 48 ÷ 144 = 12 sq ft (1.115 m²). At 6.35 mm × 2,500 kg/m³ = 15.88 kg/m², it weighs 1.115 × 15.88 = 17.70 kg, or 39.0 lb (3.25 lb per sq ft). As a double-pane unit with two 1/4 in panes, or as a single 1/2 in pane, the same size weighs twice as much: 78.0 lb.

Sources: Omni Calculator: Glass weight (densities and 40 × 40 cm aquarium example) · Calculate.co.nz: Glass weight calculator (2.5 kg/m² per mm, 2,000 × 1,000 × 10 mm example)

Frequently asked questions