Education
Area Calculator – Find the Area of a Shape
Last updated: June 19, 2026
An area calculator is a geometry utility that calculates the two-dimensional space enclosed within flat shapes. It supports various configurations including rectangles, triangles, circles, ellipses, trapezoids, and regular polygons. The calculator applies specific formulas based on dimensions like height, base, radius, and length, providing output in standard square units. Property owners, builders, landscapers, and students utilize this tool to determine surface coverage, estimate building materials, and check homework.
Pick a shape, enter its dimensions, and this area of a shape calculator returns the result along with the formula and steps.
Quick Answer
Calculate the surface area of two-dimensional shapes. Choose a shape and enter its dimensions to find the area in square units.
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
Use this area calculator to find the area of a shape, choosing from rectangle, triangle, circle, trapezoid, parallelogram, and regular polygon. The tool applies the correct formula, computes the result, and shows the steps. For more detail, open the shape's dedicated page.
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 Area Calculators
The calculator above handles common shapes in one tool. For more detailed calculations including additional measurements like perimeter, diagonal length, or surface properties, use the shape-specific calculators below.
Related Tools
- Area Formula
- Surface Area Formula
- Perimeter Formula
- Square Footage Calculator for measuring rooms, houses, and yards.
- Surface Area Calculator for 3D shapes.
- Perimeter Calculator for outline length.
- Area Converter for converting between square units.
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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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