How to Calculate Area (With Formulas, Examples & Calculator)

Whether you’re designing a garden 🪴, laying new flooring 🛠️, or helping your kid with homework 📚—knowing how to calculate area is super useful.

In this guide, we’ll break it down by shape, walk through easy examples, and give you a free calculator to do the math for you. Let’s get started!

🔢 Don’t feel like memorizing formulas? No worries! Just select the shape and plug in your numbers—our calculator will do the rest.

⚙️ Area Calculator

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📐 What Is Area?

Area is the amount of space inside a flat shape or surface.
It’s measured in square units like:

  • square centimeters (cm²)
  • square meters (m²)
  • square inches (in²)
  • square feet (ft²)

🧮 How to Calculate Area by Shape

Here are the most common shapes you’ll work with—and their formulas:

🔲 Rectangle or Square

Area = Length × Width

Example: 5m × 3m = 15 m²

🔺 Triangle

Area = ½ × Base × Height

Example: ½ × 6cm × 4cm = 12 cm²

⚪ Circle

Area = π × Radius²

Use 3.14 for π.
Example: π × 3² = 3.14 × 9 = 28.26 cm²

🪁 Parallelogram

Area = Base × Height

Same as a rectangle, just slanted!

⬠ Trapezoid

Area = ½ × (Base₁ + Base₂) × Height

Example: ½ × (6 + 4) × 5 = 25

💡 Why Is Calculating Area Important?

  • Helps with planning construction or DIY projects
  • Useful in interior design and landscaping
  • Essential for real estate and architecture
  • Teaches geometry concepts clearly

🚀 Pro Tips

  • Always use the same unit for all measurements
  • Convert inches to feet or cm to m before calculating
  • Use a calculator when dealing with decimals or π

🎯 Final Thoughts

Area doesn’t have to be confusing! Once you understand a few formulas and know which shape you’re working with, it becomes second nature.