The calculator takes in the width, height and dielectric constant of the microstrip and calculates the inductance using the formula L = (W * H) / (2 * pi * sqrt(Er)) where W is the width of the strip, H is the height of the strip, Er is the dielectric constant of the substrate. It's worth noting that this is a simple example and the real-world microstrip inductance calculator would be more complex and would include more validation, error handling and user-friendly interface. And also, this is just a basic example, to make it more useful, more functions and features can be added to it.