Simple single script to add Google’s conversion tracking to your Magento ecommerce website. The code should be added into the footer.phtml file within your current template. The code includes tracking of catalogue browsing, checkout and new orders.

Simply replace all the $googleConversionId with your actual Google Conversion ID.

<!-- Google Conversion Tracking -->
<?php $googleConversionId = ""; // Your conversion ID goes here ?>
<?php $page_type = Mage::app()->getFrontController()->getRequest()->getControllerName();
if($page_type == 'index') { ?>
 <script type="text/javascript">
 var google_tag_params = {
 ecomm_pagetype: 'home',
 ecomm_prodid: '',
 ecomm_totalvalue: 0
 };
 </script>
<?php } elseif($page_type == 'category') { ?>
 <script type="text/javascript">
 var google_tag_params = {
 ecomm_pagetype: 'category',
 ecomm_prodid: '',
 ecomm_totalvalue: 0
 };
 </script>
<?php } elseif($page_type == 'product') {
 $product_id = Mage::registry('current_product')->getId();
 $product_id = Mage::getModel('catalog/product')->load($product_id)->getSku();
 $product_price = Mage::registry('current_product')->getPrice();
 ?>
 <script type="text/javascript">
 var google_tag_params = {
 ecomm_pagetype: 'product',
 ecomm_prodid: '<?php echo $product_id; ?>',
 ecomm_totalvalue: parseFloat('<?php echo $product_price; ?>')
 };
 </script>
<?php } elseif($page_type == 'cart') { ?>
 <script>
 var id = new Array();
 var price = new Array();
 </script>
 <?php
 $cart = Mage::getModel('checkout/session')->getQuote();
 foreach ($cart->getAllItems() as $item) {
 $product_id = $item->getProductId();
 $product_id = $item->getSku();
 $product_id_all = $product_id_all.','.$product_id ;
 $productPrice = $item->getProduct()->getPrice();
 $productPrice_all = $productPrice_all.','.$productPrice;
 ?>
 <Script>
 id.push('<?php echo $product_id; ?>');
 price.push(parseFloat('<?php echo $productPrice; ?>'));
 </Script>
 <?php
 }
 $product_id_all=substr($product_id_all, 1);
 $productPrice_all=substr($productPrice_all, 1);
 ?>
 <script type="text/javascript">
 var google_tag_params = {
 ecomm_pagetype: 'cart',
 ecomm_prodid: id,
 ecomm_totalvalue: price
 };
 </script>
 <?php } elseif($page_type == 'onepage') { ?>
 <script>
 var id = new Array();
 var price = new Array();
 </script>
 <?php
 $cart = Mage::getModel('checkout/session')->getQuote();
 foreach ($cart->getAllItems() as $item)
 {
 $product_id = $item->getProductId();
 $product_id = $item->getSku();
 $product_id_all = $product_id_all.','.$product_id ;
 $productPrice = $item->getProduct()->getPrice();
 $productPrice_all = $productPrice_all.','.$productPrice;
 ?>
 <Script>
 id.push('<?php echo $product_id; ?>');
 price.push(parseFloat('<?php echo $productPrice; ?>'));
 </Script>
 <?php } 
 $product_id_all=substr($product_id_all, 1);
 $productPrice_all=substr($productPrice_all, 1);
 ?>
 <script type="text/javascript">
 var google_tag_params = {
 ecomm_pagetype: 'purchase',
 ecomm_prodid: id,
 ecomm_totalvalue: price
 };
 </script>
 <?php }else{ ?>
 <script type="text/javascript">
 var google_tag_params = {
 ecomm_pagetype: 'other',
 ecomm_prodid: '',
 ecomm_totalvalue: 0
 };
 </script>
 <?php } ?>
<script type="text/javascript">
 /* <![CDATA[ */
 var google_conversion_id = <?php echo $googleConversionId; ?>;
 var google_custom_params = window.google_tag_params;
 var google_remarketing_only = true;
 /* ]]> */
</script>
<script type="text/javascript" src="//www.googleadservices.com/pagead/conversion.js">
</script>
<noscript>
 <div style="display:inline;">
 <img height="1" width="1" style="border-style:none;" alt="" src="//googleads.g.doubleclick.net/pagead/viewthroughconversion/<?php echo $googleConversionId; ?>/?value=0&guid=ON&script=0"/>
 </div>
</noscript>
<!-- End Google Conversion Tracking -->