Square metre calculator
Work out the area of a room, or several rooms added together, in square metres and square feet.
Square feet from the legal definition of a foot.
Result
The area is 14 square metres, or 150.695 square feet.
square metres
| In square feet | 150.695 sq ft |
|---|---|
| In square yards | 16.744 sq yd |
Show the workings
| Step | Sum | Answer |
|---|---|---|
| Area | 4 m × 3.5 m | 14 m² |
| One square foot in square metres | (0.9144 ÷ 3 m)² | 0.093 m² |
| Total in square feet | 14 ÷ 0.0929 | 150.695 sq ft |
Where the figures come from
- A yard in metres: 0.914 m per yard. Source: Weights and Measures Act 1985, Schedule 1. Checked 13 November 2026.
- Feet in a yard: 3 feet per yard. Source: Weights and Measures Act 1985, Schedule 1. Checked 13 November 2026.
How to work out square metres
Multiply the length by the width, both in metres. A room 4 m long and 3.5 m wide is 4 × 3.5 = 14 square metres (m²).
If you measured in centimetres, divide each size by 100 first; in millimetres, by 1,000. A room 420 cm by 350 cm is 4.2 m × 3.5 m = 14.7 m².
For an L-shaped room, split it into two rectangles, work out each one and add them together. Use "Add another area" above to do that.
From feet to square metres
Work out the area in square feet, then multiply by 0.0929: that is how many square metres are in a square foot, from the legal definition of a foot as a third of 0.9144 metres. Or choose feet above and let the calculator do it.