Area Calculator

Calculate the area of any 2D shape. Choose a shape, enter its dimensions, and get the area and perimeter instantly. Supports rectangle, square, circle, triangle, trapezoid, ellipse, and more.

Shape Area Calculator

Area Formulas

Rectangle: A = length × width Square: A = side² Circle: A = π × r² Triangle: A = ½ × base × height Trapezoid: A = ½ × (a + b) × height Ellipse: A = π × a × b Parallelogram: A = base × height Sector: A = ½ × r² × θ (θ in radians)

Frequently Asked Questions

What is Heron's formula?+
Heron's formula calculates triangle area using only the three side lengths. If sides are a, b, c and s = (a+b+c)/2 (semi-perimeter), then Area = √(s(s−a)(s−b)(s−c)). Useful when you know all three sides but not the height.
What units does this calculator use?+
The area is in square units of whatever unit you enter (feet, meters, inches, etc.). If you enter dimensions in feet, the area is in square feet (ft²). For unit conversions, use our Unit Converter tool.

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About the Area Calculator

This free area calculator helps you get accurate results instantly without needing to work through the math manually. Whether you need a quick estimate or a precise figure, having a reliable tool on hand saves time and reduces errors compared to manual calculation.

How to Use This Calculator

  1. Enter your values in the input fields above. Each field is labeled to guide you.
  2. Double-check your inputs — results are only as accurate as the numbers you enter.
  3. Click the Calculate button to see your result instantly.
  4. Use the result for your planning, budgeting, or decision-making.

Why Accurate Calculations Matter

Small errors in math calculations can compound into significant problems. A 1% miscalculation in a budget or measurement can translate to hundreds or thousands of dollars in wasted resources, or result in having to redo work entirely. This calculator uses the standard formulas and methods to give you reliable results you can trust.

Tips for Getting the Best Results

Frequently Asked Questions

Is this calculator free? Yes — completely free with no account, login, or payment required. Use it as many times as you need.

How accurate are the results? This calculator uses the standard formulas for area calculations. Results are accurate for typical use cases. For specialized or high-stakes applications, consult a professional.

Does it work on mobile? Yes. This calculator is fully responsive and works on smartphones, tablets, and desktops.