What this calculator does
A "square" is an older real-estate area unit still used in some house plans, quotes and older property listings, particularly in Australia and New Zealand. One square equals 100 square feet, which works out to almost exactly 9.29 square metres. It has nothing to do with a geometric square shape: it is purely a unit of area, like an acre or a hectare.
The confusion this causes is straightforward: a floor plan quoted in squares looks like a small number next to the same house described in square metres, and the two get compared as if they were the same unit. A 20-square house is around 186 square metres, not 20. This converter handles the conversion in both directions using the exact factor.
The formula
One square is defined as 100 square feet. Converting to square metres multiplies by the exact factor 9.290304, which is 100 times the standard square-foot-to-square-metre conversion. Converting from square metres back to squares divides by the same factor.
| Term | Meaning |
|---|---|
| Square | A real-estate area unit equal to 100 square feet, historically used for house and building sizes. |
| Square metre | The standard metric unit of area, equal to a square one metre on each side. |
| 9.290304 | The exact number of square metres in one square, derived from the international definition of the foot. |
The inputs explained
| Field | What to enter |
|---|---|
| Convert | Choose whether you are converting squares to square metres, or square metres back to squares. |
| Amount | The amount to convert, in whichever unit you selected above. |
When to use it
Reading an older house plan or quote
Builders' quotes and older property listings sometimes still state floor area in squares. Converting to square metres makes the figure comparable with current listings and building regulations, which use metric area.
Comparing a heritage listing with a modern one
When comparing a period home advertised in squares against newer listings in square metres, converting both to the same unit avoids under- or over-estimating the size difference.
Costing per square metre from a per-square quote
A trade quote priced per square converts to a per-square-metre rate by applying the same factor, which is the unit most current material and labour costs are quoted in.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
Squares converted to square metres
A range of sizes commonly seen quoted in squares.
| Squares | Square metres |
|---|---|
| 10 sq | 92.90 m2 |
| 15 sq | 139.35 m2 |
| 20 sq | 185.81 m2 |
| 25 sq | 232.26 m2 |
| 30 sq | 278.71 m2 |
| 40 sq | 371.61 m2 |
Square metres converted back to squares
Typical modern floor areas, converted the other direction.
| Square metres | Squares |
|---|---|
| 100 m2 | 10.764 squares |
| 150 m2 | 16.146 squares |
| 200 m2 | 21.528 squares |
| 250 m2 | 26.910 squares |
| 300 m2 | 32.292 squares |
| 400 m2 | 43.056 squares |
Questions
Is a "square" the same in every country that uses it?
Where it is still used, a square is consistently defined as 100 square feet, so the conversion to square metres is the same regardless of country.
Why is it 9.290304 and not a rounder number?
It follows directly from the international foot, defined as exactly 0.3048 metres. Squaring that and multiplying by 100 gives 9.290304 square metres per square, with no rounding involved.
Is a square still used for new house plans?
Most current plans, quotes and listings use square metres. Squares mainly turn up in older documents, heritage listings, or trades that have kept the older convention.
Does a square measure land area or floor area?
It is almost always used for building or floor area rather than land size, which is more commonly quoted in square metres or hectares regardless of the building convention used.
For general area conversions between square feet and square metres, see the square metre calculator. To estimate flooring or tiling needs once you have the area in square metres, see the flooring and tiles calculator.