- 1Select your 2D shape at the top: Rectangle, Square, Circle, or Triangle.
- 2Choose your preferred length measurement unit (meters, cm, feet, inches, yards).
- 3Enter the required dimensions in the input fields to calculate exact surface area, perimeter, or circumference.
Geometric area measures the total two-dimensional surface space contained within a closed boundary. Area is expressed in squared units (such as square meters m² or square feet ft²).
Multiply length by width. Perimeter is 2 · (length + width).
Area = Length × Width | Example: 10m × 5m = 50 m²Square the length of one side. Perimeter is 4 · side.
Area = Side² | Example: 6m × 6m = 36 m²Multiply Pi (π ≈ 3.14159) by radius squared. Circumference is 2 · π · radius.
Area = π × Radius² | Example: π × (7m)² = 153.94 m²Multiply half of the base length by the perpendicular height.
Area = ½ × Base × Height | Example: ½ × 8m × 4m = 16 m²Area = 10 × 12 = 120 sq ftArea = π × 7² = 3.14159 × 49 = 153.94 sq ftArea = π × r² = π × 5² = π × 25 ≈ 78.54- Unit Consistency: Ensure all input dimensions are measured in the same unit before calculating area.
- Area Units are Squared: Area is measured in square units (m², ft², in²). Converting linear feet to square feet requires squaring.
- Positive Dimensions Only: Geometric side lengths, radii, and heights must be positive numbers (> 0).
What is the difference between area and perimeter?
Area measures the 2D surface space inside a shape (in square units). Perimeter measures the total boundary length around the outside of the shape (in linear units).
How do I calculate the area of a circle if I only have the diameter?
Divide the diameter by 2 to get the radius, then use the formula Area = π × Radius².
Why are area units squared (e.g. ft²)?
Because area represents two dimensions (length × width), multiplying two linear units together results in squared units.
Which shapes does this calculator support?
Rectangle (length × width), square (side²), circle (π × radius²), and triangle (½ × base × height). Each dimension must be a positive number.