Calculating square metres is simple: length times width. A room 4 m long and 3 m wide has an area of 4 × 3 = 12 m².
The square metre calculator, also known as a qm calculator or m² calculator, calculates the area of individual rooms, entire flats, lofts and plots of land, and also calculates costs per m² and converts between all units.
With the online square metre calculator, you can easily work out areas, floor spaces or even land prices. Even converting square metres into square centimetres, hectares or square kilometres is no problem. As an area calculator, it also works for triangles, circles and L-shaped rooms. You’ll find all the relevant formulas in this article.
Key points at a glance
- Formula: Length × width = area in square metres (m²).
- 3 × 3 metres is 9 m²; 4 × 4 metres is 16 m².
- Irregular rooms Divide it into rectangles and add up the areas.
- Roof pitch: In Switzerland, only the area with a ceiling height of 1.50 m or more is usually counted as living space.
- Convert: 1 m² = 10,000 cm², 1 hectare = 10,000 m², 1 Juchart = 3,600 m².
Calculate floor space, areas and plots of land using the square metre calculator
One square metre is the area of a square with sides measuring 1 m. The same formula applies to any rectangular area, whether it be a room, a floor, a terrace or a plot of land:
Area in m² = Length in m × Width in m
Example: How big is a plot of land that is 30 m long and 15 m wide? 30 m × 15 m = 450 m². You can work out the area in square metres by multiplying the length by the width.
In short: 2×2 metres is 4 square metres; 3×3 metres is 9 square metres.
The only important thing is that both measurements are in the same unit. If you’re measuring in centimetres, you first convert to metres: 350 cm is 3.5 m. The calculator above does this for you if you switch to «centimetres».
| Mass | Area |
|---|---|
| 2 × 2 metres | 4 m² |
| 3 × 3 metres | 9 m² |
| 4 × 3 metres | 12 m² |
| 4 × 4 metres | 16 m² |
| 5 × 5 metres | 25 m² |
| 10 × 10 metres | 100 m² (1 are) |
A square metre is written as m², and is often also written as qm or m2. It always means the same thing, whether you want to calculate qm or m².
Calculating the square metres for an entire flat
For a flat, measure each room individually and add the areas together. Measure across the floor from wall to wall, excluding door thresholds. If a room is L-shaped, calculate the area of the large rectangle and subtract the missing corner. A living room measuring 6.5 × 5 m, with a corner of 2.5 × 2 m missing, has an area of 32.5 m² − 5 m² = 27.5 m².
To do this, simply add more rooms in the calculator. It will show you the area of each room and the total.
How big are 30 or 500 square metres?
Numbers alone don’t tell the whole story. 30 m² is a square measuring roughly 5.5 × 5.5 m – the same as 2.4 car parking spaces. 500 m² is a square measuring roughly 22 × 22 m – just under two tennis courts. The calculator shows you a comparison like this for each area in the «Convert» tab.
Triangle, circle and trapezium
- Triangle: Base × height ÷ 2. A triangle with a base of 4 m and a height of 3 m has an area of 6 m².
- District: π × diameter² ÷ 4. A round flowerbed with a diameter of 2.5 m has an area of approximately 4.91 m².
- Trapezium: (long side + short side) ÷ 2 × height. With dimensions of 5 m, 3 m and a height of 3 m, that makes 12 m².
Calculating living space with sloping ceilings
In the attic, the floor area is larger than the living area. You cannot stand everywhere under a sloping ceiling, so this part is not counted, or only counted in part. The rule that applies depends on the country.
| Switzerland | Germany | |
|---|---|---|
| Basis | Housing subsidy schemes in practice, e.g. the Canton of Zurich | Housing Area Regulation (WoFlV) Section 4 |
| Counts fully | from a ceiling height of 1.50 m | for rooms with a ceiling height of 2 metres or more |
| Counts as half | nothing | 1 to just under 2 m |
| Doesn't count | under 1.50 m | less than 1 m |
Example: An attic room is 5 m long and 4 m wide, giving a floor area of 20 m². The sloping ceiling starts at the wall at a height of 0.8 m and rises at an angle of 40 degrees. The distance to the ceiling, which is 1.50 m high, is just over 80 cm. Consequently, only 15.83 m² counts as living space; around 4 m² is excluded.
If a straight sloping wall begins at a wall height of less than 1 metre, the Swiss and German rules yield exactly the same living area. It is only when the walls are higher that the German rule results in a lower figure.
That sounds like a coincidence, but it’s actually geometry: On a straight sloping surface, the half-count between 1 and 2 metres corresponds exactly to the strip between 1.50 and 2 metres. If, on the other hand, the wall is 1.20 metres high, the Swiss rule in the example gives 18.21 m², whilst the German rule gives only 17.62 m².
Ultimately, what is set out in the tenancy or purchase agreement is binding; in Switzerland, this is often calculated in accordance with the SIA 416 standard. You should therefore check property adverts to see whether the floor area or the living area is stated.
Square meter calculator convert area to side length
If you know the area and one side length, you can work out the missing side as follows:
Page a = Area ÷ side b
Example: A plot of land measures 200 m²; one side is 45 m long. The other side is 200 m² ÷ 45 m = 4.44 m.
People often ask how many «metres» 30 square metres is. You can’t convert this directly, because a square metre is an area and a metre is a length. However, you can work out how long the side of a square with that area would be: this is the square root of the area. 30 m² corresponds to a square measuring approximately 5.48 × 5.48 m, whilst 1 m² corresponds to a square measuring 1 × 1 m.
Determine prices of land with the square meter calculator
You can easily work out the price of a plot of land by multiplying its area by the price per square metre. This works in exactly the same way for floors, walls or lawns.
Costs = Plot area × price per square metre
Example: A plot of land measures 600 m²; the land costs CHF 1,850 per m². That works out at 600 × CHF 1,850 = CHF 1,110,000.
Conversely, if you divide the rent by the floor area, you get the price per m². A flat measuring 75 m² with a rent of CHF 1,800 costs CHF 24 per m² per month, or CHF 288 per m² per year. For commercial premises in Switzerland, this annual figure is usually stated in the advert. This allows you to compare offers fairly.
When it comes to floor coverings, you should allow for slightly more material than the surface area alone: usually 5 to 10 % for offcuts and a margin, or around 15 % for tiles laid in a diagonal pattern. If you want to know whether you can afford a flat or a house, the Affordability calculator. The calculator shows whether it’s worth buying rather than renting Rent or buy.
Convert QM2 calculator to cm², km² or hectare
For areas, the conversion factor increases in proportion to the square. 1 m is 100 cm, but 1 m² is 100 × 100 = 10,000 cm². Here are the most important conversions:
| Unit | In square metres |
|---|---|
| 1 square centimetre (cm²) | 0.0001 m² |
| 1 square decimetre (dm²) | 0.01 m² |
| 1 are (a) | 100 m² |
| 1 Juchart (Switzerland) | 3,600 m² |
| 1 hectare (ha) | 10,000 m² |
| 1 square kilometre (km²) | 1,000,000 m² |
| 1 square foot (sq ft) | 0.0929 m² |
| 1 acre | 4,046.86 m² |
- From square metres to square centimetres: multiply by 10,000.
- From square metres to hectares: divided by 10,000.
- From square metres to square kilometres: divided by 1,000,000.
In English property adverts, ‘sqm’ often stands for ‘square metre’. These are just standard m², so you don’t need to convert anything. It’s different with ‘sq ft’ (square feet): in that case, you divide by around 10.76 to get the figure in m².
The Juchart is an old Swiss unit of area for land. Originally, it was the area that a team of horses could plough in a day. Since 1877, the following has applied in Switzerland: 1 Juchart = 36 ares = 3,600 m². You can still come across it today in old land registry documents.
Conclusion on the square metre calculator
For most areas, multiplying the length by the width is enough to work out the square metres. Break complex shapes down into simple shapes and add them together. You need to be careful with sloping roofs, when using centimetres instead of metres, and when converting to other units. That’s exactly where the calculator saves you time and helps you avoid mistakes.
Are you still missing a conversion for areas or prices? Leave us a comment – we’ll be happy to help.
Frequently asked questions
3×3 metres – how many square metres?
With a base area of 3 × 3 metres, the total area is 9 square metres.
Which formula for calculating square metres?
To work out the square metres, multiply the length by the width of the area, both in metres. 4 m × 2.5 m equals 10 m².
How do you work out square metres?
Measure the length and width of the area in metres and multiply them together. If using centimetres, divide the measurements by 100 first. The calculator above will help you with triangles, circles and L-shaped rooms.
How do you work out the square metres when there are several rooms?
You work out the area of each room individually by multiplying its length by its width, and then add the areas together. Divide L-shaped rooms into two rectangles.
How many square metres are there in a hectare?
One hectare is 10,000 m², which is a square measuring 100 × 100 m. One are is 100 m².
How many square metres is a football pitch?
According to FIFA guidelines, a football pitch measures 105 × 68 m, which is 7,140 m². One hectare is therefore roughly 1.4 football pitches.
How many metres are there in 1 square metre?
Square metres and metres cannot be converted directly, because one is an area and the other is a length. 1 m² is equivalent to a square with sides of 1 m.
Does the area under the sloping roof count as living space?
In Switzerland, only the area above a ceiling height of 1.50 m is usually taken into account. In Germany, according to the Living Space Ordinance, the area above 2 m counts in full, that between 1 and 2 m counts as half, and that below 1 m does not count at all.