Get CGRect of a NSAttributedString

Question

I have tried many solutions provided in stackoverflow but I can't get the correct rect of a NSAttributedString.
As an instance the solution here does not work :

CGRect paragraphRect =
  [attributedText boundingRectWithSize:CGSizeMake(300.f, CGFLOAT_MAX)
  options:(NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading)
  context:nil];

Below my code :

NSMutableParagraphStyle *paragrapStyle = [[NSMutableParagraphStyle alloc] init];
paragrapStyle.alignment = NSTextAlignmentCenter;
paragrapStyle.lineHeightMultiple = 1.2;

NSMutableAttributedString *textMutableAttributedString = [[NSMutableAttributedString alloc] initWithString:textString];
[textMutableAttributedString addAttribute:NSParagraphStyleAttributeName value:paragrapStyle range:NSMakeRange(0, [textMutableAttributedString.string length])];
[textMutableAttributedString addAttribute:NSForegroundColorAttributeName value:[UIColor colorWithRed:114/255. green:132/255. blue:141/255. alpha:1] range:NSMakeRange(0,[textMutableAttributedString.string length])];
[textMutableAttributedString addAttribute:NSParagraphStyleAttributeName value:paragrapStyle range:NSMakeRange(0, [textMutableAttributedString.string length])];

NSAttributedString *textAttributedString = [[NSAttributedString alloc] initWithAttributedString:textMutableAttributedString];

[text setAttributedText:textAttributedString];

CGRect textAttributedStringRect = [textAttributedString boundingRectWithSize:CGSizeMake(text.frame.size.width, CGFLOAT_MAX)
                                                                     options:(NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading)
                                                                     context:nil];

textAttributedStringRect computed value is origin=(x=0, y=0) size=(width=260.12695, height=33.120003) while text.frame.size.width original value is 260. The computed height is completely wrong...

I have read many answers on this specific problem and none of them solve it. I hope I will have someone who knows an accurate way to calculate the rect.

Thank you for your help