Home / Area Calculator

Area Calculator

Instantly calculate the area of 8 shapes — rectangle, square, circle, triangle, trapezoid, parallelogram, ellipse and sector — with full unit conversion.

Area

-

Shape Comparison

Free Area Calculator — 8 Shapes, All Units, Instant Results

Whether you're planning a flooring project, estimating paint needed for a wall, or solving a geometry problem, calculating area accurately matters. Our free Area Calculator supports rectangles, squares, circles, triangles, trapezoids, parallelograms, ellipses, and sectors — with any input unit automatically converted into every major area unit, including acres and hectares for land measurement.

Why Use This Tool

  • Eight shape types: Rectangle, square, circle, triangle, trapezoid, parallelogram, ellipse, and sector.
  • Any input unit: mm, cm, m, km, inches, feet, or yards all supported.
  • Nine output units: mm², cm², m², km², in², ft², yd², acre, and hectare — all shown at once.
  • Live calculation: Results update automatically as you type, no need to click a button.
  • Precision control: Choose 2 to 6 decimal places for your result.
  • Shape comparison: Add multiple shapes and see which has the largest area.

Key Features

Multi-Unit Results

All 9 area units shown simultaneously, including acre & hectare.

Comparison Mode

Compare multiple shapes side by side.

Live Calculation

No button needed — results update as you type.

Step-by-Step Formula

See the formula, substitution, and final result.

Step-by-Step: How to Use

Step 1: Select your shape (rectangle, square, circle, triangle, or trapezoid).

Step 2: Enter the required dimensions and choose your input unit.

Step 3: View your area calculated instantly across all major units.

Step 4: Optionally add the result to Comparison Mode to compare multiple shapes.

Benefits

  • Removes manual geometry formula lookups for common shapes.
  • Useful for construction, landscaping, and material estimation projects.
  • Instantly compares multiple shape options for space planning.

Common Use Cases

  • Estimating flooring, tiling, or paint quantities for a room.
  • Solving geometry homework involving area calculations.
  • Comparing plot or garden shapes to determine which offers more space.
  • Planning landscaping projects requiring accurate area figures.

Privacy & Security

Calculates area for common 2D shapes using any input unit (mm to km, inch to yard) and instantly shows the result across all major area units — square meters, feet, and more. All calculations happen locally in your browser.

Frequently Asked Questions

Can I convert square meters to square feet? +
Yes, results automatically show mm², cm², m², km², in², ft², yd², acre, and hectare together.
A = π × r², where r is the radius.
Ellipse: A = π × a × b (semi-major × semi-minor axis). Sector: A = (angle ÷ 360) × π × r².
Yes, the area recalculates live as you type — no need to click the Calculate button, though it's still there if you prefer.
Yes, click "Add to Comparison" to build a side-by-side list with the largest highlighted.
Rectangle, square, circle, triangle, trapezoid, parallelogram, ellipse, and sector — 8 shapes in total.
A = ½ × base × height.
Yes, mm, cm, m, km, inches, feet, or yards.
A = ½ × (base1 + base2) × height.
Yes, the result grid includes acre and hectare, ideal for land and property measurements.
Yes, completely free with unlimited calculations.
No, all calculations happen locally in your browser.
Yes, commonly used to estimate flooring, paint, or turf quantities.

Related Tools

Also try our Land Measurement Tool and Length Converter.

Ready to calculate area? Choose your shape above — free and instant.

Share Your Experience

Found this tool useful? Have a suggestion or found a bug? Send your feedback directly to us — we read every message.