Glass Weight Calculator
This glass weight calculator multiplies the size and thickness of a pane by the density of the glass: window and float glass, borosilicate glass, acrylic sheet or your own value. It gives the weight of one pane and of all panes, the weight per area and the volume.
Example: Material: Float / window glass (soda-lime, 2.5 g/cm³) · Unit for width and height: inches (in) · Width 36 · Height 24 · Thickness (mm; in inches when the unit is inches) 0.25 · Number of panes 1 → Weight: Glass weight: 19.51 lb (8.85 kg). Source: Wikipedia, Kalk-Natron-Glas: density about 2.5 g/cm³ (read 15.10.2026). Updated: .
How it is calculated
Glass weight = width × height × thickness × density. Window and float glass has a density of about 2.5 g/cm³, so every millimeter of thickness weighs 2.5 kg per square meter. A 36 × 24 in pane of 1/4 in glass weighs 19.51 lb (8.85 kg).
Examples (float glass)
| Size | Thickness | Weight |
|---|---|---|
| 36 × 24 in | 0.25 in | 19.51 lb |
| 48 × 36 in | 0.25 in | 39.02 lb |
| 60 × 30 in | 0.5 in | 81.29 lb |
| 100 × 50 cm | 6 mm | 7.5 kg |
Rule of thumb: 1/4 in float glass weighs about 3.25 lb per square foot, 1/2 in twice that.
Densities
- Soda-lime glass (window, float, mirror): about 2.5 g/cm³ – 2.53 g/cm³ measured for flat (float) glass.
- Borosilicate glass (lab glass, oven doors): about 2.23 g/cm³.
- Acrylic (PMMA, plexiglass): 1.17 to 1.20 g/cm³ – less than half the weight of glass.
For double glazing add the weight of each pane: two 4 mm panes weigh like one 8 mm pane. A full tank of water outweighs its glass many times over – see the aquarium volume calculator. Other materials are covered by the density calculator and the steel weight calculator.
Handling
Large panes get heavy fast: 2 × 1 m of 10 mm glass already weighs 50 kg. Plan lifting aids and a second person for anything above about 25 kg.
Frequently asked questions
How do I calculate the weight of glass?
Multiply area by thickness and density. In metric terms: square meters × thickness in mm × 2.5 = kg. 1 m² of 6 mm glass weighs 15 kg.
How much does 1/4 inch glass weigh per square foot?
About 3.25 lb per square foot for float glass; 3/8 in about 4.9 lb and 1/2 in about 6.5 lb.
What is the density of glass?
Window and float glass (soda-lime) about 2.5 g/cm³ or 2,500 kg/m³; borosilicate about 2.23 g/cm³.
Is acrylic lighter than glass?
Yes. Acrylic has a density of about 1.19 g/cm³, so a sheet weighs less than half as much as glass of the same size.
How heavy is a double-glazed window?
Add the panes: 4 mm + 4 mm glass weighs about 20 kg per square meter, plus the frame and spacer.
Sources and legal basis
- Wikipedia, Kalk-Natron-Glas: density about 2.5 g/cm³ (read 15.10.2026)
- Wikipedia, Soda–lime glass: density at 20 °C 2.53 g/cm³ (flat glass; container glass 2.52) (read 15.10.2026)
- Wikipedia, Borosilicate glass: density about 2.23 g/cm³ (read 15.10.2026)
- Wikipedia, Poly(methyl methacrylate): density 1.17–1.20 g/cm³ (read 15.10.2026)
- NIST Special Publication 811, Appendix B.8: inch = 2.54 E−02 m, pound (avoirdupois) = 4.535 924 E−01 kg (read 15.10.2026)
As of: · Editorial policy
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