About Units

Acre: An acre is a unit of area commonly used in the United States and the United Kingdom. It is equal to 4,840 square yards or 43,560 square feet. The term "acre" comes from an Old English word meaning "field" and was originally used to measure a piece of land that could be plowed in one day by a yoke of oxen.

Square kilometer: A square kilometer is a unit of area in the metric system. It is equal to 1,000,000 square meters or approximately 0.3861 square miles. This unit is commonly used to measure large areas such as geographical regions, city extents, or country sizes. One square kilometer is roughly equivalent to 247 acres.