Why are macro %'s different from app to website?

Just wondering why my macro percentages are different from the app on my phone (where I add everything) and the website when I just look at it randomly. For example today, on my phone my macros show c/f/p 36%/27%/37% but on the website my macros show c/f/p 41%/26%/33%. I wouldn't ask if it was just a digit - but 36 to 41 is a bit of a range when it comes to macros, and 33-37 the same. Just wondering which one is correct. And if it's a rounding thing and the app and the website are rounding differently, why not change one so they round the same? Little frustrating.