Square Mile (mi²)
The square mile, or mi², is the area of a square one mile on each side, or 640 acres. Its history dates back to the mile, which originated in Roman times. The square mile became a set measurement in England. It is still widely used in the US and the UK for large areas, such as cities, counties, and parks. Most countries use square kilometers, but in English-speaking regions, the square mile remains common, especially in historical and legal contexts.
Square Meter (m²)
The square meter, or m², is the basic unit of area in the metric system. It is the area of a square with sides one meter long. First used in France in the late 1700s, it helped make measurements simpler and the same everywhere. Today, the square meter is the primary unit of measurement for areas, including rooms, buildings, and land. Its accuracy and clear links to other metric units make it a key unit in building, real estate, design, and science.