not at all vs one hundred percent

not at all

adv
  • Not in the least. 

intj
  • Used similarly to you're welcome, as a conventional reply to an expression of gratitude. 

  • Don't worry about it (response to worry or an apology) 

one hundred percent

adj
  • Complete, entire, whole, perfect. 

  • Completely sure. 

  • Used other than figuratively or idiomatically: see one hundred, percent. 

  • Well, good, okay. 

adv
  • Totally, completely. 

How often have the words not at all and one hundred percent occurred in a corpus of books? (source: Google Ngram Viewer )