Square Footage Calculator
Calculate area for rectangles, circles, triangles, and irregular rooms — and convert between units.
Your details
Options
This calculator runs entirely on your device. Nothing you enter is uploaded, stored, or sold. How this works
Total area
280.00 ft²
20.00 × 14.00 ft
Includes your inputs, the full breakdown, and every row of the table.
Square yards
31.11
Square metres
26.01
Acres
0.0064
Square inches
40,320
| Unit | Value |
|---|---|
| Square feet | 280.00 |
| Square inches | 40,320 |
| Square yards | 31.111 |
| Square metres | 26.013 |
| Acres | 0.00643 |
| Hectares | 0.002601 |
What this means
- For irregular rooms, break the space into rectangles and triangles, calculate each separately, and add the results. The L-shape option handles the most common case.
- Measure to the inside face of walls for flooring and paint. For real estate square footage, exterior dimensions and different measurement standards apply.
How the square footage calculation works
Square footage underpins nearly every construction estimate: flooring, paint, tile, sod, roofing, and concrete all start with area. Rectangular areas are length times width; circles are πr²; triangles are half base times height.
The practical skill is decomposition. Almost any real room can be split into rectangles plus the occasional triangle. Calculate each piece, sum them, and you have an accurate area without any complicated geometry.
Frequently asked questions
How do I calculate square footage of an irregular room?
Divide it into rectangles and triangles along the walls, compute each area separately, and add them together. Subtract any interior obstructions like islands or built-ins.
How many square feet in a square yard?
Nine. Carpet is often priced per square yard, so divide your square footage by nine to compare against per-square-foot pricing.
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Disclaimer. This calculator is provided for general information and educational purposes only and does not constitute financial, tax, legal, medical, or engineering advice. Results are estimates based on the inputs you provide and the assumptions described above. Confirm any figure with a qualified professional before acting on it.