The square meter (m²) is the SI base unit of area, equal to a square measuring one meter on each side, used worldwide for real estate, construction, and land surveying. Apartment sizes, office floor plans, and construction costs are almost universally quoted in square meters outside the United States. One square meter equals approximately 10.764 square feet.

The square mile (mi²) is a large imperial area unit equal to 640 acres or about 2.59 square kilometers, used for measuring expansive territories like cities, counties, and national parks. Geographic data in the United States and United Kingdom frequently references square miles when describing regions, especially in population density calculations. One square mile equals exactly 2.58999 square kilometers.