The math is simple, no need to be a genious. All you need to know is how to add numbers.
Add up the ratings you currently have for def, sh and abs. That's your total.
Take that total. Look up the relevant table in the first post. Find the closest total.
Then, the next three numbers are your def, shi and abs that you should have.
If you still have dififculties with this, tell us what your current def, shield and absorb ratings are, we'll tell you what they should be.