Convert Square Millimeters (mm²) to Square Inches (in²)
Enter a value below to convert Square Millimeters (mm²) to Square Inches (in²).
Conversion:
1 Square Millimeters (mm²) = 0.0015500031 Square Inches (in²)
How to Convert Square Millimeters (mm²) to Square Inches (in²)
1 mm2 = 0.0015500031 in2
1 in2 = 645.16 mm2
Example: convert 15 Square Millimeters (mm²) to Square Inches (in²):
25 mm2 = 0.0387500775 in2
Square Millimeters (mm²) to Square Inches (in²) Conversion Table
| Square Millimeters (mm²) | Square Inches (in²) |
|---|---|
| 0.01 mm2 | 0.000015500031 in2 |
| 0.1 mm2 | 0.00015500031 in2 |
| 1 mm2 | 0.0015500031 in2 |
| 2 mm2 | 0.0031000062 in2 |
| 3 mm2 | 0.0046500093 in2 |
| 5 mm2 | 0.0077500155 in2 |
| 10 mm2 | 0.015500031 in2 |
| 20 mm2 | 0.031000062 in2 |
| 50 mm2 | 0.077500155 in2 |
| 100 mm2 | 0.15500031 in2 |
| 1000 mm2 | 1.5500031 in2 |
Square Millimeters (mm²)
Definition
A square millimeter (mm²) is a metric unit of area equal to the area of a square with sides of 1 millimeter. It equals 0.000001 square meters (10⁻⁶ m²) and is part of the International System of Units (SI).
History
The square millimeter derives from the metric system established during the French Revolution in the late 18th century. As a sub-unit of the square meter, it became widely adopted for precision measurements in engineering and manufacturing with the rise of industrialization.
Current use
Square millimeters are commonly used in engineering, electronics, and manufacturing to measure very small surfaces — such as cross-sections of wires, microchip areas, and precision mechanical parts.
Square Inches (in²)
Definition
A square inch (in²) is an imperial unit of area equal to the area of a square with sides of 1 inch. It equals approximately 6.4516 square centimeters.
History
The square inch evolved from the British imperial system. The inch itself was historically defined as the width of a man's thumb, and was standardized to exactly 25.4 mm in 1959 by international agreement.
Current use
Square inches are used in the United States and the United Kingdom for measuring the area of small objects, cross-sections, screen sizes, pressure specifications (PSI), and manufacturing tolerances.