Area of a square or regular hexagon from one side (mm) — plus the equal-area shape you asked for, read out in mm and inches.
Enter the side in millimeters (default 25.4 mm = 1 inch). Readouts show both mm and inches (1 in = 25.4 mm). Both shapes are drawn to the same scale, so equal areas cover equal space. Hexagon area = (3√3 / 2) · side².