Online calculator to calculate the area A and the circumference C of an ellipse, given by the formula
and 
are the semi axes of the ellipse.
Note that the circumference is given by an infinite sum (series) and therefore cannot be calculated exactly. But taking a large number N of terms in the series, will ensure that the circumference is obtained with a good accuracy. You have the possibility of changing N in the calculator below and see how C converges towards a "fixed value" as you increase N.
(0 or greater) and (0 or greater) and N (integer, 1 or greater) the number of terms in the series and press "calculate".