Free online geometry tools
Free Geometry Calculator – Area, Perimeter, Angles & More
Calculate area, perimeter, circumference, volume, surface area, angles, and other geometry measurements with our free online geometry calculators.
Interactive tool
Geometry Calculator
Choose a shape, enter its measurements, and get the result with the formula.
Your result
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Geometry Calculator: Area, Perimeter, Angles & More
Geometry is the study of shapes, sizes, positions, and the relationships between them. The calculator above handles several common two-dimensional and three-dimensional shapes so you can check a measurement without leaving the page.
Area vs. perimeter
Area measures the amount of surface inside a two-dimensional shape, while perimeter measures the total distance around its boundary. A rectangle with length 8 and width 3 has an area of 24 square units and a perimeter of 22 units.
2D vs. 3D measurements
Two-dimensional shapes commonly use area and perimeter or circumference. Three-dimensional solids use volume and surface area. For example, a cube with side length 4 has volume 64 cubic units and surface area 96 square units.
Common geometry formulas
Circle: A = πr² and C = 2πr
Triangle: A = ½ × base × height
Rhombus: A = ½ × d₁ × d₂
Cylinder: V = πr²h
How to use the calculator
Select a shape, enter the measurements shown, and choose Calculate. The tool validates numeric input and displays the result together with the formula used.
Geometry in everyday life
Geometry appears in floor plans, construction, packaging, landscaping, engineering, art, sports, and measurement. Knowing which formula matches a shape is often the first step; keeping units consistent is just as important.
Geometry Shapes
Quadrilaterals
Rhombus properties, angles, diagonals and comparisons.
Formulas & Examples
See rhombus examples and step-by-step calculations.
Practice
Try rhombus practice questions with answers.
Featured Rhombus Guides
Rhombus Area
Clear definitions, formulas, examples and related links.
Rhombus Perimeter
Clear definitions, formulas, examples and related links.
Rhombus Diagonals
Clear definitions, formulas, examples and related links.
Rhombus Angles
Clear definitions, formulas, examples and related links.
Rhombus vs Square
Clear definitions, formulas, examples and related links.
Rhombus vs Parallelogram
Clear definitions, formulas, examples and related links.
Frequently Asked Questions
What is the difference between area and perimeter?
Area measures the inside of a two-dimensional shape; perimeter measures the distance around it.
Does the calculator require an account?
No. Calculations run in your browser and do not require an external API.
Can I enter decimals?
Yes. The calculator accepts decimal measurements.