Circular Mil
A circular mil is a unit of area used mainly to measure the cross-sectional area of round wires and cables in electrical engineering.
Defined as the area of a circle with a diameter of 1 mil (1 mil = 0.001 inch).
Area = (diameter in mils)² circular mils.
1 circular mil ≈ 7.854 × 10⁻¹⁰ square meters or 0.7854 square mils.
Circular mils simplify calculations for round wires since area scales with the square of the diameter.
Square Decimeter [dm²]
A square decimeter (dm²) is a unit of area equal to a square with sides 1 decimeter (10 centimeters) long.
1 dm² = 0.01 m² = 100 cm².
It is commonly used to measure small surfaces, such as the area of tiles or sheets of paper.