Area Calculator
Use the calculators below to find the area of seven common shapes. Useful for estimating land area, floor plans, and geometry homework.
Rectangle
Triangle
Enter three side lengths (Heron's formula). For other parameters use the Triangle Calculator.
Trapezoid
Circle
Sector
Ellipse
Parallelogram
Related
Quick formulas
Rectangle: l×w
Circle: πr²
Trapezoid: (b₁+b₂)h/2
What is area?
Area measures the two-dimensional space inside a shape, expressed in square units (ft², m², in², etc.). It is essential for construction, landscaping, real estate, and geometry.
Area formulas by shape
- Rectangle: A = length × width
- Triangle: A = √[s(s−a)(s−b)(s−c)] (Heron's formula)
- Trapezoid: A = (b₁ + b₂) × h / 2
- Circle: A = πr²
- Sector: A = ½r²θ (θ in radians) = ½r² × (degrees × π/180)
- Ellipse: A = πab (a, b = semi-axes)
- Parallelogram: A = base × height
Real-world uses
- Land & property: Estimate plot size in square feet or meters.
- Flooring & paint: Calculate room floor area for materials.
- Agriculture: Field area for crop planning.
- Engineering: Cross-sectional areas in design.
Frequently Asked Questions
Use the Triangle section with Heron's formula, or the full Triangle Calculator for angles too.
Feet, meters, inches, yards, and centimeters. Results are shown in matching square units.