The hectare (ha) is a metric unit of area equal to 10,000 square meters or 100 ares, widely used in agriculture, forestry, and land management worldwide. Farms, vineyards, and nature reserves are typically described in hectares across Europe, Asia, and Oceania. One hectare equals approximately 2.471 acres, providing a convenient bridge between metric and imperial land measurements.

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.