How to Calculate the Circumference of an Oval

How to Calculate the Circumference of an Oval
••• shilh/iStock/GettyImages

An oval looks like an elongated circle and is most commonly called an ellipse in geometry. Although there is no single, simple formula for calculating the circumference of an ellipse, one formula is more accurate than others. If you know the major axis and the minor axis of an ellipse, you can work out the circumference using the formula

C = 2π × \sqrt{\frac{a^2 + b^2}{2}}

where ​a​ is the major axis and ​b​ is the minor axis. The major axis spans the length of the ellipse, running through the center and connecting the two farthest points, while the minor axis sits perpendicular to the major axis and connects the two closest points.

    Note the major and minor axes of your ellipse and find the exponent of both. For example, if your major axis is 12 inches and your minor axis is 8 inches, work out

    (12 × 12) + (8 × 8) = 208

    Work out

    \frac{208}{2} = 104

    Insert this value into your formula. The next step is to work out

    C = 2π × \sqrt{104}

    The value of π (pi) never changes. It is always 3.142. Work out 2 × 3.142 = 6.284. Insert this value into your formula. The next step is to work out

    C = 6.284 × \sqrt{104}

    Use a scientific or online calculator to find the square root of 104, which is 10.198. Insert this value into your formula. Work out

    6.284 × 10.198 = 64.084

    You now know that the circumference of the ellipse is 64.084 inches.

    Tips

    • Check your answer by using an online circumference of ellipse calculator. Input the major axis and minor axis and compare the circumference of ellipse to your answer.

Related Articles

How to Calculate the Area of an Oval
How to Calculate Circumference in Inches
How to Calculate Cubic Inches in a Cylinder
How to Find the Height of a Rhombus
How to Find the Length of the Sides of an Octagon Based...
How to Find the Radius
How to Find the Radius of a Cone
How to Find the Radius of a Partial Circle
How to Calculate Ellipse Eccentricity
How to Calculate the Length of a Curved Line
How to Find the Circumference of an Octagon
How to Divide a Circle Into Thirds
How to Calculate Outside Diameter
How to Find the Radius of an Arc
How to Determine the Diameter of a Circle
How to Calculate Volume of a Circular Cylinder
How to Find the Volume of a Sphere in Terms of Pi
How to Calculate Eccentricity
How to Calculate the Radius and Diameter of an Oval
How to Convert 7/8 Inches to mm