What Is Area and Why It Matters
Area is the amount of two-dimensional space enclosed within a shape's boundary, measured in square units such as square feet (ft²), square meters (m²) or acres. It's one of the most practically useful measurements in everyday life — used to estimate flooring and tiles, paint quantity, land value, crop yield, fabric needed for a project, or the size of a room, plot or field.
Area Formulas for Every Shape
Here's a quick reference for every shape this calculator supports:
| Shape | Area Formula | Perimeter / Boundary |
|---|---|---|
| Square | a² | 4a |
| Rectangle | l × w | 2(l + w) |
| Circle | π r² | 2π r |
| Triangle | ½ × b × h | a + b + c (if sides known) |
| Parallelogram | b × h | 2(a + b) |
| Trapezoid | ½ × (a + b) × h | sum of all four sides |
| Rhombus | ½ × d₁ × d₂ | 4 × side |
| Ellipse | π × a × b | Ramanujan's approximation |
| Circular Sector | (θ/360) × π r² | 2r + arc length |
| Regular Polygon | (n × s²) / (4 × tan(π/n)) | n × s |
| Annulus (Ring) | π(R² − r²) | 2π(R + r) |
Area vs Perimeter
Area and perimeter are often confused but measure different things. Area tells you how much surface a shape covers (in square units), while perimeter tells you the total distance around its edge (in linear units). Two shapes can have the same perimeter but very different areas, and vice versa — which is why both numbers matter for construction, fencing and material estimates.
Measuring an Irregular Plot
- Break the plot into simple shapes (rectangles, triangles) and add up each area.
- Use a regular polygon approximation for roughly circular or multi-sided plots.
- For accurate land records, use a GPS/total-station survey or your local revenue department's map.
- Always double-check boundary measurements before any legal transaction.
Understanding Indian Land Measurement Units
India uses several traditional land units alongside the metric system, and the same unit can mean a different area depending on the state. This calculator uses commonly cited standardised values — always confirm local figures with your state's land records before a transaction.
| Unit | Approx. in Sq. Feet | Commonly Used In |
|---|---|---|
| Acre | 43,560 sq ft | Pan-India, agricultural land |
| Hectare | 107,639 sq ft | Govt. land records, forestry |
| Bigha | ~27,000 sq ft (varies by state) | UP, Bihar, Rajasthan, MP, WB |
| Guntha / Gunta | ~1,089 sq ft | Maharashtra, Karnataka, Telangana |
| Cent | 435.6 sq ft | Tamil Nadu, Kerala, Karnataka, AP |
| Kanal | 5,445 sq ft | Punjab, Haryana, HP, J&K |
| Marla | 272.25 sq ft | Punjab, Haryana (house plots) |
| Ground | 2,400 sq ft | Tamil Nadu (Chennai) |
| Ankanam | ~72 sq ft | Andhra Pradesh, Telangana |