Instantly calculate the perimeter of an ellipse (also known as its circumference) with our easy-to-use online calculator. Simply input the semi-major axis and semi-minor axis to get accurate results for your geometric, engineering, or design needs. Understand the formula and how to find the ellipse perimeter quickly.
Formula:
The perimeter (circumference) of an ellipse does not have a simple exact formula, but can be approximated using various methods. This calculator uses Ramanujan's first approximation:
P ≈ π [3(a+b) - √((3a+b)(a+3b))]
- P: Perimeter (circumference) of the ellipse
- π: Pi (approximately 3.14159)
- a: Length of the semi-major axis
- b: Length of the semi-minor axis