Ellipse Area Calculator

Calculate the area of an ellipse using semi-major and semi-minor axes

Calculate Ellipse Area

Half of the longest diameter

Half of the shortest diameter

Choose measurement unit

Ellipse Properties

47.12
cm² (Area)
25.53
cm (Perimeter)

Area in Different Units

4712.39
mm²
47.12
cm²
0.00
7.30
in²
0.05
ft²

Formula Used

Area = π × a × b

Where a = 5.000 cm (semi-major axis), b = 3.000 cm (semi-minor axis)

Area = π × 5.000 × 3.000 = 47.1239 cm²

0.8000
Eccentricity (e)
4.000
Focal Distance (cm)
4.000
Linear Eccentricity (cm)

Example Calculation

Garden Ellipse Example

Problem: You want to plant an elliptical garden

Given: Semi-major axis = 8 meters, Semi-minor axis = 5 meters

Find: Area of the garden

Solution

Using the ellipse area formula: A = π × a × b

A = π × 8 × 5

A = π × 40

A = 125.66 square meters

This means you need about 126 m² of planting area.

Ellipse Diagram

ab
Semi-major axis (a)
Semi-minor axis (b)

Key Formulas

Area

A = π × a × b

Perimeter (approx.)

P ≈ π(a + b)

Ramanujan's approximation used

Eccentricity

e = √(1 - b²/a²)

Common Ellipse Examples

Earth's Orbit
Semi-major: ~150M km
Eccentricity: ~0.017
Standard Track
400m oval track
Semi-major: ~84m
Football Field
Australian Rules
Approximate ellipse shape

Tips & Facts

Semi-major axis (a) is always ≥ semi-minor axis (b)

When a = b, the ellipse becomes a circle

Eccentricity ranges from 0 (circle) to 1 (parabola)

Ellipses are conic sections formed by slicing a cone

Understanding Ellipses

What is an Ellipse?

An ellipse is an oval-shaped curve that looks like a squashed circle. It's defined as the set of all points where the sum of distances to two fixed points (called foci) is constant. Ellipses appear frequently in nature, from planetary orbits to the shape of shadows.

Key Components

  • Semi-major axis (a): Half of the longest diameter
  • Semi-minor axis (b): Half of the shortest diameter
  • Foci: Two fixed points that define the ellipse
  • Center: The midpoint between the foci

Area Formula Derivation

The area formula A = πab comes from calculus:

1. Start with the ellipse equation: x²/a² + y²/b² = 1

2. Solve for y: y = b√(1 - x²/a²)

3. Integrate from -a to a

4. Result: A = πab

Real-World Applications

  • Astronomy: Planetary and satellite orbits
  • Architecture: Arches and domes
  • Engineering: Gears and cam profiles
  • Art: Perspective drawing and design