Area Calculator for 9 Shapes with Formula and Steps
Pick a shape, enter its measurements and choose a unit. You get the area, a labelled diagram and the formula worked out step by step.
- Nothing you type is stored
- Free
- No signup
Area
96m²
- Perimeter
- 40 m
- Area in m²
- 96 m²
- Area in sq ft
- 1,033.3354 ft²
Show working
- A = l × b
- A = 12 × 8 = 96 m²
How to use
- Choose the shape.
- Enter the measurements shown in the diagram and pick a length unit.
- Read the area; open "Show working" to see each step.
Good to know
Formulas used: square a², rectangle l × b, triangle ½ × b × h, circle πr², trapezium ½(a + b)h, parallelogram b × h, rhombus ½ × d₁ × d₂, ellipse πab and sector (θ/360°) × πr². These are the mensuration formulas taught from NCERT Class 6 to Class 10.
All lengths must be in the same unit. The area comes out in that unit squared (cm², m², ft²), and is also converted to m² and square feet, which is handy for room and plot sizes in India.
The diagram is drawn to proportion for flat shapes so you can check you entered the right side. For a circle-based shape you can switch π to 22/7 or 3.14 to match a textbook answer.
Questions
What is the formula for the area of a triangle?
Area = ½ × base × height, where the height is measured at right angles to the base. If you only know the three sides, use the triangle calculator, which uses Heron's formula.
How do I convert square metres to square feet?
1 m² = 10.7639 sq ft. This calculator shows both automatically, whatever unit you enter.
Why does my answer differ slightly from the book?
Books often use π = 22/7 or 3.14. Choose the same value under "More options" to match exactly.
What is the area of a trapezium?
Half the sum of the parallel sides multiplied by the distance between them: ½ × (a + b) × h.
Is anything I enter stored?
No. The calculation runs in your browser and nothing is sent to a server.