Select a shape, enter dimensions, and get the area instantly.
Area Formulas Reference
| Shape | Formula | Variables |
|---|
| Rectangle | L × W | L = length, W = width |
| Circle | π × r² | r = radius |
| Triangle | ½ × b × h | b = base, h = height |
| Trapezoid | ½ × (a + b) × h | a, b = parallel sides, h = height |
| Ellipse | π × a × b | a, b = semi-axes |
| Parallelogram | b × h | b = base, h = height |
| Sector | (θ/360) × π × r² | θ = angle°, r = radius |
Area Unit Conversions
| From | To | Multiply by |
|---|
| sq ft | sq m | 0.0929 |
| sq m | sq ft | 10.764 |
| sq ft | acres | 0.0000229568 |
| acres | sq ft | 43,560 |
| sq mi | acres | 640 |
| hectares | acres | 2.471 |
Practical Area Estimates
A standard parking space is 8.5 × 18 ft = 153 sq ft. A basketball court is 4,700 sq ft. A football field (including end zones) is 57,600 sq ft, or 1.32 acres. The average US home lot is 0.2 acres (8,712 sq ft). These benchmarks help when you need a rough mental picture of area without exact measurements.
How to Use This Area Calculator
Select a shape (rectangle, triangle, circle, trapezoid, ellipse) and enter the required dimensions. The calculator shows the area and perimeter instantly.
Formula & How It Works
Rectangle: A = length × width. Triangle: A = ½ × base × height. Circle: A = π × r². Trapezoid: A = ½ × (a + b) × h. Ellipse: A = π × a × b.
Calculation Example
Rectangular room 12 ft × 15 ft: Area = 180 sq ft. A circular garden with 8-ft radius: Area = π × 64 = 201.1 sq ft.
Expert Tips
For irregular shapes, split into basic shapes and add the areas. Convert all measurements to the same unit before calculating. 1 acre = 43,560 sq ft.