Implement your heightForRowAtIndexPath
like this:
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
NSString *text = [dataArray objectAtIndex:indexPath.row]; //your data string
CGSize constraint = CGSizeMake(yourLabel.frame.size.width, 2000.0f);
CGSize size;
NSStringDrawingContext *context = [[NSStringDrawingContext alloc] init];
CGSize boundingBox = [text boundingRectWithSize:constraint
options:NSStringDrawingUsesLineFragmentOrigin
attributes:@{NSFontAttributeName:yourLabel.font}
context:context].size;
size = CGSizeMake(ceil(boundingBox.width), ceil(boundingBox.height));
return size.height;
}