Calculate and convert area for various 2D geometric shapes with different units
A triangle is a polygon with three edges and three vertices. It's one of the basic shapes in geometry.
Area is the quantity that expresses the extent of a two-dimensional figure or shape in the plane. It is the measure of how much space there is inside a shape.
Area is measured in square units, such as square meters (m²), square centimeters (cm²), square inches (in²), etc.
Different shapes have different formulas for calculating their area based on their properties. For example:
| Shape | Formula | Variables |
|---|---|---|
| Square | A = a² | a = side length |
| Rectangle | A = l × w | l = length, w = width |
| Triangle | A = ½ × b × h | b = base, h = height |
| Circle | A = π × r² | r = radius |
| Ellipse | A = π × a × b | a = semi-major axis, b = semi-minor axis |
| Trapezoid | A = ½ × (a + b) × h | a, b = parallel sides, h = height |
Calculate the area of a rectangle with length 8 cm and width 5 cm.
Solution: A = l × w = 8 cm × 5 cm = 40 cm²
Calculate the area of a circle with radius 3 m.
Solution: A = π × r² ≈ 3.1416 × (3 m)² ≈ 28.27 m²
Convert 1 acre to square meters.
Solution: 1 acre = 4,046.86 m²
This area calculator helps you with everyday measurement tasks by providing instant calculations for:
Calculate flooring for a 12×15 ft room: Select Rectangle → Enter 12 and 15 → Choose ft² → Convert to m² for tile purchases.
Plan a triangular flower bed: Select Triangle → Enter base 8 ft and height 6 ft → Convert ft² to m² for soil calculation.
Compare circle areas: Calculate pizza sizes using Circle shape → Enter different radii → Compare areas in in².
After calculating the area for your floor plan or garden, you might also need to determine the capacity of a planter box or a room. For that, explore our tool to calculate the volume of common 3D shapes.
A: Conversions use standard mathematical constants and conversion factors. For everyday use, precision to 2-3 decimal places is sufficient. For engineering or scientific purposes, use higher precision settings.
A: This tool handles standard geometric shapes. For irregular shapes, break them into regular shapes (triangles, rectangles), calculate each area separately, then add them together.
A: Adjust the "Decimal Precision" dropdown to control how many decimal places are shown. For most practical purposes, 2 decimal places is ideal.
A: Use a measuring tape for larger items or a ruler for smaller ones. Always measure in straight lines, and for triangles, ensure height is measured perpendicular to the base.
A: Use the "Copy to Clipboard" button to save results, or take a screenshot. The tool doesn't store calculations between sessions.
If you're working with standard units like acres or hectares for land plots, our dedicated modern area converter provides quick conversions between these units without the shape calculations.
Accuracy Disclaimer: This tool provides mathematical calculations based on standard formulas. For critical applications (construction, legal documents, scientific research), verify results with professional tools and consider measurement tolerances. Always double-check important calculations.
Device Compatibility: Works on all modern browsers (Chrome, Firefox, Safari, Edge) and devices (desktop, tablet, mobile). No plugins or downloads required.
Update Notice (Nov 2025): This version includes enhanced explanations, practical examples, and accessibility improvements. Calculation formulas remain unchanged for consistency.
🙏 Wait! Before You Go...
🎉 Loved this tool? Help others discover it by sharing:
👍 Like or Subscribe for updates: