Area Calculator FAQ
What is the formula for the area of an ellipse?
The formula for the area of an ellipse is A = piab, where a is the semi-major axis and b is the semi-minor axis.
How do I calculate the area of an ellipse?
Measure the semi-major axis and semi-minor axis, then multiply a x b x pi. The calculator does this instantly when you enter the two axis values.
Can I use the full major and minor axes instead of semi-axes?
Yes. Switch to full axes mode and use the equivalent formula A = piAB / 4, where A and B are the full major and minor axis lengths.
What is the difference between the major axis and the semi-major axis?
The major axis is the full longest width of the ellipse. The semi-major axis is half of that length, measured from the centre to the edge.
What is the difference between the minor axis and the semi-minor axis?
The minor axis is the full shortest width of the ellipse. The semi-minor axis is half of that length, measured from the centre to the edge.
Can I find one ellipse axis from the area and the other axis?
Yes. If you know the area and one axis value, the calculator can reverse the ellipse area formula to find the missing axis.
Example: what is the area of an ellipse with semi-major axis 10 cm and semi-minor axis 6 cm?
If a = 10 cm and b = 6 cm, the area is about 188.496 cm^2. The exact form is 60pi cm^2.
