Area Calculator: Square Metres and Square Feet for Any Shape
Area is the amount of surface inside a two-dimensional shape, measured in square units. This calculator covers rectangles, triangles, circles and trapezoids — the shapes that account for nearly all real-world flooring, painting, landscaping and material estimates.
The formulas you need
- Rectangle or square: length × width.
- Triangle: ½ × base × height (height measured perpendicular to the base).
- Circle: π × radius². Remember radius is half the diameter.
- Trapezoid: ½ × (base₁ + base₂) × height.
Breaking down awkward rooms
L-shaped and irregular spaces are handled by splitting them into rectangles, calculating each separately and adding the results. Subtract areas you will not cover — kitchen islands, stairwells, fixed cabinets — rather than paying for material you cannot use.
Units and waste allowance
One square metre is about 10.764 square feet. To convert, multiply square metres by 10.764 or divide square feet by the same number. When ordering materials, add 5-10% for straight-lay tile or flooring and up to 15% for diagonal or herringbone patterns, plus enough for future repairs from the same batch.
Key takeaways — Area Calculator
- Measure in one unit system throughout, then convert once at the end.
- Split complex spaces into simple shapes and add the areas.
- Always add a waste allowance before ordering materials.