What is the distance (in miles) of the earth's orbit around the sun?

The mean orbital radius is close to 150,000,000 km, approximate the orbit as circular and use this to calculate the circumference. Then convert to miles.

Hello ElijahD

Although the answer you received is correct, the earth orbit is not perfectly circular : it's eliptical. So there is more to it ! The minimum distance is 146 M Km (91 M Miles) and the maximum distance is 152 M Km (or 94,5 M Miles).

Finding the exact solution to the lenth of the perimeter of an ellipse is a very difficult problem. You can approximate it as:


P \approx \pi * \sqrt {2(a^2+b^2) - (a-b)^2 /2 }


where a and b are the semi-major and semi-minor axis lengths. If you do the math you'll find that Capuchin's approximation technique gets you within 0.5% of what this formula gives - for most purposes this is probably "good enough," especially given the uncertinty in the rounded off numbers that Sarnian provided for the semi-major and semi-minor axis lengths.