Square Foot (US Survey)
The square foot (US survey) is a unit of area based on the US survey foot, which is slightly longer than the international foot. It is mainly used in land surveying and mapping in the United States.
1 US survey foot = 1200⁄3937 meters (approximately 0.3048006096 m)
1 square foot (US survey) ≈ 0.0929034116 m²
This unit helps maintain consistency in US land measurements, especially in legal and cadastral contexts.
Square Nanometer [nm²]
A square nanometer (nm²) is a unit of area equal to a square with sides 1 nanometer long (1 nm = 1 billionth of a meter, or 10⁻⁹ m).
It’s used to measure extremely tiny areas, like the surface of molecules or nanomaterials.
1 nm² = 1 × 10⁻¹⁸ m².