Education
Area Calculator
Pick a shape, enter its dimensions, and the calculator returns the area along with the formula used and a one-line step.
Shape
e.g. 8
e.g. 5
This is a hub. For perimeter, diagonals, and shape-specific extras, follow the link to each shape's dedicated page.
Area
40
8 × 5 = 40
Hub view. For perimeter, diagonals, angles, and special-case details, open the shape-specific calculator linked below.
Examples
Rectangle 8 × 5
area 40
Triangle base 10, height 6
area 30
Circle r = 5
area ≈ 78.540
Hexagon side 5
area ≈ 64.952
How it works
Each shape has its own area formula. The hub picks the right formula based on the shape you select, runs the arithmetic, and shows a clear single-line step. For more detail on any shape, open its dedicated calculator.
Rectangle · A = length × width
Triangle · A = base × height ÷ 2
Circle · A = πr²
Trapezoid · A = ((base 1 + base 2) ÷ 2) × height
Parallelogram · A = base × height
Regular polygon · A = (n × s²) ÷ (4 × tan(π ÷ n))
Shape-specific calculators
- Rectangle calculator for area, perimeter, diagonal, and aspect ratio.
- Triangle area calculator with base & height, Heron, and SAS methods.
- Circle calculator for radius, diameter, circumference, and area.
- Trapezoid calculator for area and perimeter from bases, height, and legs.
- Parallelogram calculator for area, perimeter, and interior angle.
- Regular polygon calculator for area, perimeter, apothem, and interior/exterior angles.
- Right triangle calculator with all four solve-from modes.
- Perimeter calculator hub for perimeter and circumference.
- Surface area calculator for 3D shapes.
- All education calculators.
Frequently asked questions
Area is the amount of 2D space inside a flat shape, measured in square units. A rectangle that is 8 by 5 units covers 40 square units of space; a circle of radius 5 covers about 78.54 square units.
Rectangle, triangle (base and height), circle, trapezoid, parallelogram, and regular polygon. For more advanced cases (Heron's formula on three sides, SAS triangle area, right-triangle solving), follow the link to the dedicated shape calculator below.
Use this hub when you want a quick answer across mixed shapes without switching tabs. Use the dedicated shape page when you also need perimeter, diagonals, angles, apothem, or worked-example detail.
Whatever units you used for the inputs. If you entered inches, the area is in square inches. If you entered meters, it is in square meters. The calculator does not convert units; keep all inputs consistent.
Rectangle: A = length × width. Triangle: A = base × height ÷ 2. Circle: A = π × r². Trapezoid: A = ((base 1 + base 2) ÷ 2) × height. Parallelogram: A = base × height. Regular polygon: A = (n × s²) ÷ (4 × tan(π ÷ n)).
Not directly. For 3D surface area (cube, sphere, cylinder, cone, pyramid, rectangular prism), use the surface area calculator. For 3D volume, use the volume calculator. This hub is 2D only.
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