home

[] The Earth's **D**iameter is **7926.41** miles.

To calculate the surface area of Earth, you use geometry. The formula for the surface of a sphere is However, only about **57** million square miles of this land. Given that there are 640 acres in a square mile, that's about **36.48** billion acres. However, because of climate and soil conditions, only **12** million square miles or **7.68** billion acres of all land is **arable** land.
 * pi x** **Diamater****²**. The diameter of the Earth is 7926.28 miles at the equator and 7,899.80 miles through the poles making the Earth nearly a perfect sphere.**So pi = 3.14159265358979 x (7926.28 miles)² is about 197.38 **** million square miles . **

Use the population clock [] to find out how many people are on Earth right now. Divide the 7.68 billion acres of arable land by the number of people to discover how many acres each person has for the production of all food and plant products (wood for paper, housing and furniture) required throughout their lifetime.

(An acre is an area of land equal to 43,560 square feet. For visuality purposes, an acre is most often compared to the size of a football field - not counting the two end zones, which are each 30 feet in length.)