How to convert Square millimeter to Square inch

Conversion factor and calculation steps from Square millimeter (mm²) to Square inch (sq in).

Conversion logic

Each unit is defined via the base unit (square meter (m²)). The value is first converted to the base unit, then to the selected unit.

1 mm² = 1.00000000e-6 m²

1 sq in = 0.00064516 m²

1 mm² × 1.00000000e-6 = 1.00000000e-6 m²

1.00000000e-6 m² ÷ 0.00064516 = 0.00155000310001 sq in