Area Calculator
Calculate the area of circles, rectangles, triangles, trapezoids, ellipses, and more
CircleA = π × r²
Area
Enter dimensions to calculate area
Formula Reference
| Shape | Formula | Variables |
|---|---|---|
| Circle | A = π × r² | Radius (r) |
| Rectangle | A = w × h | Width (w), Height (h) |
| Square | A = s² | Side (s) |
| Triangle | A = (b × h) / 2 | Base (b), Height (h) |
| Right Triangle | A = (a × b) / 2 | Leg a, Leg b |
| Trapezoid | A = ((a + b) × h) / 2 | Base a, Base b, Height (h) |
| Parallelogram | A = b × h | Base (b), Height (h) |
| Ellipse | A = π × a × b | Semi-axis a, Semi-axis b |
| Regular Hexagon | A = (3√3 / 2) × s² | Side (s) |
Frequently asked questions
What is the formula for the area of a circle?
A = π × r², where r is the radius. For example, a circle with radius 5 cm has an area of π × 25 ≈ 78.54 cm².
How do I calculate the area of a triangle?
For any triangle with a known base and height: A = (base × height) / 2. For a right triangle, the two legs serve as base and height, so A = (leg a × leg b) / 2.
What is the area of a trapezoid?
A = ((a + b) × h) / 2, where a and b are the two parallel bases and h is the perpendicular height between them.
What units can I use?
You can enter dimensions in any unit (mm, cm, m, inches, feet) — just stay consistent within a calculation. The result will be in the squared version of whichever unit you select.