TableView cell size to with respect to label size

I have a UITableView and have my own custom cell containing a UILabel inside the cell.

I want to increase the tableView row size according to the text in the label. I am using AutoLayout and my label have 20 padding from left and 8 padding from right,top and bottom.

I am stuck here because the label context is some time small and sometimes very large and i want to increase the size of that row when the text is increased.