The diameter of Jupiter at the equator is 88,846 miles, and its diameter at the poles is 83,082 miles. The difference in measurement is due to the rapid spinning of the planet, which completes one rotation in about 9 hours and 50 minutes at the equatorial region and around 9 hours and 56 minutes at the polar regions.
Jupiter is the largest and the fastest spinning planet in the solar system. Scientists estimate that Jupiter is 318 times more massive than Earth. Despite its immense size, Jupiter has the shortest days due to its high rotational speed. Compared to the poles, the planet's equator turns faster, which forms a bulge around it that accounts for the oblate spheroid shape of Jupiter.