How to Calculate Pipe Slope & Invert Elevations Getting pipe from Point A to Point B isn’t difficult on paper. Getting it there at the right line and grade, while maintaining slope through structures, crossings, changing depths, and real field conditions, is where the work begins. A foreman doesn’t need to be a surveyor or engineer. But if you’re responsible for installing pipe, you should understand the math well enough to answer three basic questions: Where am I starting? W