According to the CIA World Factbook:
126 billion acres on planet Earth.
6.9 billion people on planet Earth.
= 18.26 acres of planet Earth per person. This is where you get all your water and fuel and oxygen from.
Surface of Earth is ~70.9% water.
= 5.3 acres of dry land per person — includes desert, tundra, rock. This is where you live and work, and includes your share of a parking space at work and at your favorite shopping mall, your favorite grocery store, and anywhere else that you park or drive or otherwise occasionally take up space.
Only 11% of land is arable.
= .585 acre of arable land per person ( a square about 160 feet on each side, as wide as a football field and about half as long) — Pretty much ALL your food (fruit, veggies, meat, milk–not seafood) (as well as cotton for clothes) comes from that.
That’s if you spread it out equally. Currently, each American has 1.48 acres of arable land, if you spread out all America equally for all Americans. Chinese folks get .265 arable acres each. That’s a square 107.4 feet on a side.
I’m getting claustrophic.