📐 Geometry Calculator

Calculate areas, perimeters, volumes, and surface areas for geometric shapes with our free, comprehensive Geometry Calculator. Get accurate results with formula explanations for educational and professional use.

Select the shape you want to calculate
Choose what you want to calculate
Enter the radius of the circle
Enter the length of the rectangle
Enter the width of the rectangle
Enter the side length of the square
Choose how to calculate triangle area
Enter the base of the triangle
Enter the height of the triangle
Enter the length of side A
Enter the length of side B
Enter the length of side C
Enter the radius of the sphere
Enter the radius of the cylinder
Enter the height of the cylinder
Enter the radius of the cone base
Enter the height of the cone
Enter the side length of the cube
Enter the length of the rectangular prism
Enter the width of the rectangular prism
Enter the height of the rectangular prism

How to Use This Geometry Calculator

How to Use the Geometry Calculator:

  1. Select the geometric shape you want to calculate (circle, rectangle, triangle, etc.)
  2. Choose the calculation type (area, perimeter, volume, surface area)
  3. Enter the required dimensions in the input fields that appear
  4. Results calculate automatically with formula explanations
  5. Copy results or download calculations for your records

Pro Tips: All calculations show the mathematical formula used, helping you learn and verify results. For triangles, ensure the three sides can form a valid triangle. For 3D shapes, both volume and surface area calculations are available.

How It Works

Geometry Calculation Formulas:

Our calculator uses standard geometric formulas taught in mathematics curricula worldwide:

  1. Circle: Area = π × r², Circumference = 2 × π × r
  2. Rectangle: Area = length × width, Perimeter = 2 × (length + width)
  3. Triangle: Area = ½ × base × height, or Heron's formula for three sides
  4. Sphere: Volume = (4/3) × π × r³, Surface Area = 4 × π × r²
  5. Cylinder: Volume = π × r² × height, Surface Area = 2π × r × (r + height)

Example: For a circle with radius 5 units:

  • Area = π × 5² = 3.14159 × 25 = 78.54 square units
  • Circumference = 2 × π × 5 = 2 × 3.14159 × 5 = 31.42 units
  • Educational Value: Understanding these formulas helps in real-world applications

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Frequently Asked Questions

How accurate are the geometry calculations?

Our calculator uses precise mathematical formulas with high-precision floating-point arithmetic. Results are accurate to multiple decimal places, suitable for academic, professional, and practical applications. All calculations follow standard geometric principles and mathematical conventions.

What shapes and calculations are supported?

We support comprehensive calculations for 2D shapes (circles, rectangles, squares, triangles) and 3D solids (spheres, cylinders, cones, cubes, rectangular prisms). Each shape includes area, perimeter/circumference, and volume calculations where applicable.

Can I use this calculator for homework and tests?

Yes! Our calculator is designed for educational use and provides not just answers but also shows the formulas used. This helps you understand the mathematical principles and verify your manual calculations. Always check with your instructor about calculator policies for specific assignments or exams.

Are the formulas mathematically correct?

Absolutely. All calculations use standard geometric formulas taught in mathematics curricula worldwide. For example, circle area uses π×r², triangle area uses ½×base×height, and sphere volume uses (4/3)×π×r³. Each result can be verified against textbook formulas.