How can I show the amount saved in magento 2

Try this in design/frontend/Vendor_Name/Theme_Name/Magento_Catalog/templates/product/list.phtml

 $regprice = $_product->getPrice();  
 $specialprice = $_product->getSpecialPrice();  
 $yousave = number_format((float)($regprice - $specialprice), 2, '.', '');  
 $yousavepct = number_format((float)(100*(($regprice - $specialprice)/$regprice)), 0);  
 if($yousave > 0): ?>  
   <p class="you-save-statement">You save: $<?php echo $yousave; ?> (<?php echo $yousavepct; ?>%)</p>  
 <?php endif; ?>