What is the point of calculus?
If you're going into fields of science such as physics, chemistry, engineering, or higher mathematics, calculus is crucial. Calculus is the study of rates of change of things that algebra alone can't fully explain. Calculus is also linked very strongly to areas and volumes of shapes and solids.
In higher level mathematics, this concept translates to (say) finding areas and volumes of any solid, as well as quantifying various attributes of vector fields. Physicists use calculus (among other techniques) to work out the motion of moving things, and (perhaps most famously) the motion of planets and stellar bodies. Engineers use acceleration - a number not always easily obtained with dials - in their calculations of their designs, so that they can design objects, products, and structures that won't fall apart. And so on.
Calculus is mostly important in the sciences, but if you look around you, you can see other applications of calculus inside and outside your home.