Area and Perimeter Calculator
Select a shape, enter its measurements and calculate the area and perimeter instantly.
Area and perimeter formulas
These are the formulas used for each shape:
| Shape | Area | Perimeter |
|---|---|---|
| Square | l² | 4 × l |
| Rectangle | b × h | 2 × (b + h) |
| Triangle | (b × h) / 2 | a + b + c |
| Circle | π × r² | 2 × π × r |
| Trapezoid | ((B + b) × h) / 2 | B + b + l₁ + l₂ |
| Rhombus | (d₁ × d₂) / 2 | 4 × l |
| Ellipse | π × a × b | ≈ π × (3(a+b) − √((3a+b)(a+3b))) |
| Regular pentagon | (P × a) / 2 | 5 × l |
| Regular hexagon | (3√3 / 2) × l² | 6 × l |
What is area and perimeter used for?
🏠 Home renovation
Calculate square metres of flooring, paint, tiles or lawn to budget materials accurately.
🌱 Gardening and land
Know the area of a garden or plot for planting, fencing or calculating irrigation needs.
📐 Design and plans
Verify surfaces in architectural plans, interior design or engineering projects.
📚 Study and exams
Solve geometry exercises from secondary school, sixth form and university quickly.
Frequently asked questions about area and perimeter
What is the difference between area and perimeter?
The perimeter is the total length of the outline (metres, cm...). The area is the surface the shape occupies (square metres, cm²...).
What is the formula for the area of a circle?
Area = π × r². The perimeter (circumference) is 2 × π × r.
How is the area of a triangle calculated?
Area = (base × height) / 2. The height must be perpendicular to the base.
How is the area of a trapezoid calculated?
Area = ((major base + minor base) × height) / 2.