WooCommerce - Show cart weight

<table>
<tr class="total weight">
<th><strong><?php _e('Total Weight', 'woocommerce'); ?></strong></th>
<td><strong>
<?php
  $total_weight = $woocommerce->cart->cart_contents_weight;
  $total_weight .= ' '.get_option('woocommerce_weight_unit');
  echo $total_weight;
?>
</strong></td>
</tr>
</table>