How Many Square Feet in an Acre of Land?

There are 43,560 square feet in a acre; this is 4,840 square yards.

You can find a conversion calculator at http://www.unitconversion.org/area/acres-to-square-foots-conversion.html Originally, the size of an acre was approximately the amount of land an ox could plow in a day.  Now, I don’t know about you, but that approximation means virtually nothing to me.  Today, the easiest visualization might be the sideline to sideline area of 90.75 yards of a standard american football field. 

Lot sizes are commonly measured in acres or a fraction thereof.  A typical suburban residential lot would measure 0.15 – 0.50 acres.  As you move to more rural areas 5, 10, 20, 40, and 80 acre parcels are very common.