I would be wanting to not have curved and angled sections so maybe start by simplifying the layout . Are you DIYing the install ?

Your profile says you are a GC? How out of square is it? Order the pavers for it sqaure and use that as your overage/waste.

"professional trick"

As a pro, drawing the footprint and pattern in a CAD program is key. You will still have to use an adequate overage, but by actually drawing it you can also figure out conflicts in how the pattern relates to those curves, make sure something like a table's chair legs won't be sitting on a soldier course, or most importantly have dimensional references, centerpoints, arcs, etc communicated so whoever is installing it isn't winging it in the field.

This is pretty easy math. Turn your picture into circles/semicircles/partial circles and rectangles. Calculate the ares of each and add them up. I'd bet your learned it in middle school geometry. You can look up the formulas, if you don't remember them.