Square Footage Calculator
Calculate area in square feet, square meters, and square yards. Add multiple rooms or shapes and get a running total instantly.
How to use Square Footage Calculator
The square footage calculator computes the area of rooms, plots and irregular spaces in square feet, square metres, square yards and acres. It handles rectangles, triangles, circles, trapezoids and L-shaped rooms, and lets you add multiple areas together — useful for flooring, tiling, landscaping and real estate calculations.
- Select the shape of the space: rectangle, triangle, circle, trapezoid or L-shape.
- Enter the required dimensions.
- Add multiple rooms or sections using the "Add area" button.
- Review total area in all unit formats.
Your data never leaves your device — 100% private processing.
Area formulas for common shapes
Rectangle: length × width. Triangle: 0.5 × base × height. Circle: π × radius². Trapezoid: 0.5 × (a + b) × height. L-shape: split into two rectangles and sum. To convert: 1 sq yard = 9 sq ft; 1 sq metre = 10.764 sq ft; 1 acre = 43,560 sq ft. For flooring and tiling, always add 10–15% waste factor on top of the net area.
| From | To sq ft | To sq metres | To sq yards |
|---|---|---|---|
| 1 sq ft | 1 | 0.0929 | 0.111 |
| 1 sq metre | 10.764 | 1 | 1.196 |
| 1 sq yard | 9 | 0.836 | 1 |
| 1 acre | 43,560 | 4,047 | 4,840 |
Flooring and tiling — waste factors
Ordering flooring without waste factor leads to shortfalls that may require reordering from a different dye lot. Standard waste allowances: hardwood or laminate with straight lay — 10%; diagonal or herringbone lay — 15%; ceramic/porcelain tile (straight) — 10%; tile (diagonal) — 15%; carpet (with seaming) — 10–15%. Round up to the nearest standard roll or box size.
Glossary
- Dye lot
- A manufacturing batch; tiles or flooring from different lots may have slight colour variations.
- Net area
- The actual floor or wall area, excluding waste and overlap.
- Gross area
- Net area plus a waste factor — the amount to actually purchase.
- Linear foot
- A length measurement (1 foot long); different from square footage.
Related reading
Frequently Asked Questions
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Why use Square Footage Calculator?
- Accurate material estimates reduce waste and over-ordering
- Supports both metric and imperial measurements
- Covers common materials: concrete, lumber, flooring, paint
- Results include waste factor buffers for professional accuracy
Common use cases
- Calculate concrete needed for a driveway
- Estimate flooring tiles for a room renovation
- Work out paint quantity for interior walls
- Calculate lumber needs for a deck project
- Estimate roofing material for a pitched roof
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