Read 2 Samuel 14:26 Using Other Translations
And when he polled his head, (for it was at every year's end that he polled it: because the hair was heavy on him, therefore he polled it:) he weighed the hair of his head at two hundred shekels after the king's weight.
And when he cut the hair of his head (for at the end of every year he used to cut it; when it was heavy on him, he cut it), he weighed the hair of his head, two hundred shekels by the king's weight.
He cut his hair only once a year, and then only because it was so heavy. When he weighed it out, it came to five pounds!