# What is the glass weight?

Glass weight calculator: the weight of a pane or sheet of flat, float, tempered or borosilicate glass from its length, width and thickness, with the weight per square foot and per square metre.

- Page: https://www.acalculator.org/construction/glass-weight-calculator
- JSON spec: https://www.acalculator.org/construction/glass-weight-calculator.json
- Version: ed8fded4ae4d

## Default answer

Example with the default inputs (Length 48 in, Width 36 in, Thickness 0.25 in, Panes 1, Glass Flat, float or window glass, 2,530 kg/m³): The glass weighs 39.486 lb (3.29 lb per square foot).

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| l | Length | The length of one pane. |
| w | Width | The width of one pane. |
| t | Thickness | The thickness of the glass, such as 1/4 in or 6 mm. |
| n | Panes | How many panes of this size. |
| g | Glass | The kind of glass, which sets the density. Tempered and laminated float glass weigh about the same as float glass. |
| rho | Density | The density of the glass. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| total | Total weight | Weight of one pane × panes. |
| piece | Weight of one pane | Length × width × thickness × density. |
| perSqFt | Weight per square foot | Pounds per square foot at this thickness. |
| perSqM | Weight per square metre | Kilograms per square metre at this thickness. |
| area | Glass area | Length × width × panes. |

## Method

Weight = length × width × thickness × density × panes. Per square metre = thickness × density; per square foot = that × 0.09290304 ÷ 0.45359237.

## Assumptions

- Flat, float and window glass (soda-lime) is 2,530 kg/m³ (158 lb/ft³); borosilicate glass is 2,230 kg/m³. Tempered and laminated float glass weigh about the same as float glass; type a density for anything else.
- The pane is a flat rectangle; frames, edges and interlayers are not counted.

## Worked examples

1. l = 1.2192, w = 0.9144, t = 0.00635, n = 1, g = flat gives piece = 17.910405, perSqFt = 3.290474, perSqM = 16.0655. Source: Wikipedia, Soda–lime glass, properties table: flat glass density 2.53 g/cm³ at 20 °C, https://en.wikipedia.org/wiki/Soda%E2%80%93lime_glass (retrieved 2026-10-03).
2. l = 1, w = 0.5, t = 0.005, n = 4, g = boro gives total = 22.3, perSqM = 11.15. Source: Wikipedia, Borosilicate glass: about 2.23 g/cm³, https://en.wikipedia.org/wiki/Borosilicate_glass (retrieved 2026-10-03).
3. l = 0.6096, w = 0.6096, t = 0.01, n = 1, g = custom, rho = 2,500 gives piece = 9.290304, perSqM = 25. Source: 0.01 m × 2,500 kg/m³ = 25 kg/m² × 0.37161216 m² (4 ft²; NIST SP 811 Appendix B, 1 ft = 0.3048 m, https://www.nist.gov/pml/special-publication-811, retrieved 2026-10-03) = 9.290304 kg.

## FAQ

### How do I calculate the weight of glass?

Multiply length × width × thickness to get the volume, then multiply by the density. Flat (float) glass is about 2,530 kg/m³. A 48 × 36 in pane of 1/4 in glass is 1.1148 m² × 0.00635 m × 2,530 = 17.9 kg, or 39.5 lb.

### How much does glass weigh per square foot?

About 13.2 lb per square foot for each inch of thickness. 1/8 in float glass is about 1.65 lb/ft², 1/4 in about 3.29 lb/ft², 1/2 in about 6.58 lb/ft².

### Is tempered glass heavier than regular glass?

No. Tempering is a heat treatment that does not change the glass or its density, so a tempered pane weighs the same as a float pane of the same size and thickness.

### What is the density of glass?

Flat, float and window glass (soda-lime) is about 2.53 g/cm³ (2,530 kg/m³, 158 lb/ft³). Borosilicate glass is lighter, about 2.23 g/cm³.

### How much does 1 m² of 6 mm glass weigh?

0.006 × 2,530 = 15.18 kg per square metre for float glass, and 13.38 kg for borosilicate.

### Does laminated glass weigh more?

Only a little. The thin plastic interlayer is lighter than glass, so a laminated pane weighs about the same as float glass of the same total thickness. Use the custom density if you know the maker’s figure.

## Sources

- Wikipedia, Soda–lime glass, properties table: flat glass density 2.53 g/cm³ at 20 °C, retrieved 2026-10-03. https://en.wikipedia.org/wiki/Soda%E2%80%93lime_glass
- Wikipedia, Borosilicate glass: density about 2.23 g/cm³, retrieved 2026-10-03. https://en.wikipedia.org/wiki/Borosilicate_glass
- NIST Special Publication 811 (2008), Appendix B: 1 in = 0.0254 m, 1 ft = 0.3048 m, 1 lb = 0.45359237 kg exactly, retrieved 2026-10-03. https://www.nist.gov/pml/special-publication-811