The square centimeter (cm²) is a metric area unit equal to one ten-thousandth of a square meter, commonly used in medical reports, lab measurements, and small product specifications. Skin lesion sizes, fabric swatches, and circuit board components are often measured in square centimeters. One square centimeter equals exactly 0.155 square inches.

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.