- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
	CGFloat		result = 44.0f;
	NSString*	text = nil;
	CGFloat		width = 0;
	CGFloat		tableViewWidth;
	CGRect		bounds = [UIScreen mainScreen].bounds;
	
	if (UIInterfaceOrientationIsPortrait(self.interfaceOrientation))
		tableViewWidth = bounds.size.width;
	else
		tableViewWidth = bounds.size.height;

	width = tableViewWidth - 110;		// fudge factor
	text = [self textForRow:indexPath.row];
	
	if (text)
	{
		// The notes can be of any height
		// This needs to work for both portrait and landscape orientations.
		// Calls to the table view to get the current cell and the rect for the 
		// current row are recursive and call back this method.
		CGSize		textSize = { width, 20000.0f };		// width and height of text area
		CGSize		size = [text sizeWithFont:[UIFont systemFontOfSize:12.0f] constrainedToSize:textSize lineBreakMode:UILineBreakModeWordWrap];

		size.height += 29.0f;			// top and bottom margin
		result = MAX(size.height, 44.0f);	// at least one row
	}
	
	return result;
}

How to work out the cell height of a piece of text in order to set the row height of a table dynamically.

Dynamic Cell Height

Objective C