AREA • SHAPES • CONVERSIONS
Square Meter Calculator
Calculate area in m² from dimensions, convert existing area units and add an optional material allowance with every step shown.
CLEAR CALCULATION METHODOLOGY
How to calculate square metres
A square metre, written m², measures area rather than length. For a rectangular floor, wall or plot, first express both dimensions in metres, then multiply length by width.
If the measurements are entered in centimetres, feet, inches, millimetres or yards, the calculator converts each linear dimension to metres before calculating area. This is important because a linear conversion factor must be squared when converting an existing area.
Square-metre formulas for common shapes
Rectangle or square
length × widthFor a square, use the same number for length and width.
Circle
π × radius²Radius is half the diameter.
Triangle
base × perpendicular height ÷ 2Use the height measured at a right angle to the base.
Trapezoid
(side A + side B) ÷ 2 × heightSides A and B must be the parallel sides.
For an irregular room or plot, divide the outline into simple shapes, calculate each part and add the areas. Keep all measurements in the same unit for each calculation.
Square metre conversion table
| Convert 1 square metre to | Equivalent | Conversion from m² |
|---|---|---|
| Square feet | 10.7639 ft² | m² × 10.7639 |
| Square yards | 1.1960 yd² | m² × 1.1960 |
| Square centimetres | 10,000 cm² | m² × 10,000 |
| Hectares | 0.0001 ha | m² ÷ 10,000 |
| Acres | 0.000247105 acres | m² ÷ 4,046.8564 |
Conversion results are displayed with useful decimal precision while the underlying calculation retains greater precision.
Worked square metre example
The 10% allowance is only an example. Flooring, tiles, paint coverage and construction materials can require different allowances depending on the product, pattern and cuts.
Practical measuring tips
- Measure length and width along straight, consistent edges.
- Use the same unit for every dimension in one shape.
- Measure the perpendicular height for triangles and trapezoids.
- Calculate alcoves and extensions as separate rectangles.
- Subtract openings only when the material will not cover them.
- Confirm the supplier’s pack coverage and rounding rules before ordering.
Square meter calculator FAQs
How do I calculate square metres?
For a rectangle, convert the length and width to metres and multiply them. A room that is 5 metres long and 4 metres wide has an area of 20 square metres.
How many square feet are in one square metre?
One square metre equals approximately 10.7639 square feet. Multiply square metres by 10.7639 to convert to square feet.
Is a square metre the same as a metre?
No. A metre measures one-dimensional length. A square metre measures two-dimensional area and represents a square that is one metre long and one metre wide.
How do I calculate square metres from centimetres?
Convert each linear centimetre measurement to metres by dividing by 100, then calculate the area. For an existing square-centimetre area, divide by 10,000 to obtain square metres.
How much waste allowance should I add?
The suitable allowance depends on the material, layout, cuts, pattern and installer. The calculator applies any percentage you enter, but it does not prescribe a percentage. Confirm ordering requirements with the supplier or installer.
How do I measure an irregular room?
Divide the room into rectangles, triangles or other simple shapes, calculate each area separately and add the results. Subtract openings only when they should not be covered.
Can I use feet or inches for the measurements?
Yes. Select feet, inches or another supported length unit. The calculator converts every dimension to metres before applying the selected shape formula.
Does the area converter change length units or area units?
The shape calculator accepts length units such as feet and metres. The converter accepts existing area units such as square feet, square yards, hectares and acres. These are different types of conversion.