Glass · Mirrors
Mirror weight calculator
A mirror weighs 2.5 kg per square metre for every millimetre of glass: a 4 mm mirror is 10 kg/m² (2.05 lb per square foot). A 600 × 900 mm bathroom mirror in 4 mm weighs 5.4 kg; a 600 × 1800 mm full-length one, 10.8 kg; a round one 800 mm across, 5.0 kg. A frame adds its own weight per metre round the edge.
—
Mirror weight
— kg
Glass
— kg
Frame
— kg
On each hook
— kg
How it is worked out
weight = area × thickness (mm) × 2.5 kg/m² + frame (kg/m) × perimeter
area: rectangle w·h · round π·d²/4 · oval π·w·h/4
on each hook = weight / number of hooks
Mirror is float glass, 2500 kg/m³ (EN 572-1), with a silvered coat and backing paint too thin to change the figure. For the mirror above: 0.6 × 0.9 × 4 × 2.5 = 5.40 kg. A 1000 × 2000 mm mirror in 6 mm is 30 kg: that one needs two people and a wall that can take it.
Mirror weight by size and thickness
| Size (mm) | 3 mm | 4 mm | 5 mm | 6 mm |
|---|---|---|---|---|
| 400 × 600 | 1.8 | 2.4 | 3.0 | 3.6 |
| 500 × 700 | 2.6 | 3.5 | 4.4 | 5.2 |
| 600 × 900 | 4.1 | 5.4 | 6.8 | 8.1 |
| 400 × 1500 | 4.5 | 6.0 | 7.5 | 9.0 |
| 600 × 1800 | 8.1 | 10.8 | 13.5 | 16.2 |
| 800 × 1200 | 7.2 | 9.6 | 12.0 | 14.4 |
| 1000 × 2000 | 15.0 | 20.0 | 25.0 | 30.0 |
Weights in kg, glass only. For pounds, multiply by 2.2.
What this page does not do
- It does not rate the fixings. The load on each hook is the weight shared out; what a plug holds in plasterboard or tile is on its own datasheet.
- It does not weigh a backing board. A mirror glued to MDF or plywood carries the board's weight too: the sheet weight calculator has it.
Questions people ask
- How much does a mirror weigh?
- 2.5 kg per square metre for each millimetre of thickness: a 4 mm mirror weighs 10 kg/m², a 6 mm one 15 kg/m². A 600 × 900 mm mirror in 4 mm weighs 5.4 kg.
- How heavy is a full-length mirror?
- A frameless 600 × 1800 mm mirror in 4 mm weighs 10.8 kg (23.8 lb); with a frame, add its weight per metre times the 4.8 m round the edge.
- How much does a 6mm mirror weigh per square foot?
- 1.39 kg (3.07 lb) per square foot, or 15 kg per square metre. A 1/4 inch mirror is the same glass.
- How much does a round mirror weigh?
- A round mirror 800 mm across in 4 mm weighs 5.0 kg: π × 0.4² × 4 × 2.5.