Shopify - Add percentage saved to the price in the Select callback.

gistfile1.txt

---Find the select callback:

var selectCallback = function(variant, selector) {
      if (variant && variant.available) {

---Add this with the select callback:

var per_saved = ((variant.compare_at_price - variant.price)/variant.compare_at_price)* 100.0;

$('.options .price').html('<strong>'+Shopify.formatMoney(variant.price, "{{shop.money_with_currency_format }}").toString().replace(',', '.') + '</strong><span class="compare_at_price"><del>' + Shopify.formatMoney(variant.compare_at_price, "{{shop.money_with_currency_format}}").toString().replace(',', '.') + '</del><br>You save ' + per_saved + '%</span>');