Perimeter Calculator
Calculate the perimeter of various shapes with unit conversions
Calculator
Select a shape and enter its dimensions.
About the Perimeter Calculator
The Perimeter Calculator is a online tool that allows you to calculate the perimeter or boundary length of multiple geometric shapes including rectangles, circles, triangles, ellipses, trapezoids, regular polygons, and annuli (rings). It supports common engineering and geometry units such as meters (m), centimeters (cm), and millimeters (mm), allowing for quick calculations.
What You Can Calculate
- Rectangle Perimeter: Total length around a rectangle — useful for walls, rooms, or layouts.
- Circle Perimeter (Circumference): Boundary length of pipes, cylinders, or curved edges.
- Triangle Perimeter: Calculate total side length for trusses, roofs, or frameworks.
- Ellipse Perimeter: Estimate curved edge lengths of ovals and elliptical designs.
- Trapezoid Perimeter: Useful for irregular plots, ramp profiles, and civil structures.
- Regular Polygon Perimeter: Compute multi-sided shapes such as hexagons or octagons with any number of sides.
- Annulus (Ring) Perimeter: Find the combined circumference of inner and outer circular edges.
Formulas Used in the Calculator
Depending on the selected shape, the calculator applies standard geometry formulas for perimeter:
- Rectangle: P = 2 × (L + W)
- Circle: P = 2 × π × R
- Triangle: P = A + B + C
- Ellipse (Ramanujan Approximation): P ≈ π × [3(a + b) − √((3a + b)(a + 3b))]
- Trapezoid: P = a + b + c + d
- Regular Polygon: P = n × s
- Annulus (Ring): P = 2 × π × (R + r)
How to Use the Perimeter Calculator
- Select a shape from the dropdown list.
- Enter the required dimensions (length, width, sides, or radius).
- Choose your preferred unit of measurement (m, cm, or mm).
- The tool automatically computes and displays the perimeter in meters (m).
You can quickly switch shapes and units, and the calculator instantly updates results, helping you save time and prevent manual errors.
Applications of Perimeter Calculation
Perimeter is a core measurement used in geometry, design, and engineering. Understanding the total boundary length of shapes is crucial for:
- Construction and Architecture: Estimating wall, fence, and floor edging dimensions.
- Mechanical Engineering: Designing circular shafts, gaskets, and structural components.
- Electrical Engineering: Planning wire or coil lengths and conductor arrangements.
- Landscaping and Planning: Measuring borders of gardens, pavements, and pathways.
- Education and Learning: Practicing geometry concepts, verifying problems, and teaching area-perimeter relationships.
The calculator is equally helpful for students, architects, engineers, and DIY enthusiasts needing fast, accurate perimeter measurements.