Jquery Original Gravity

jq-original-gravity.js

$('#btn_og').click(function() {
   //get form values
   temp_val = $('#og_wort_temp').val();
   og_val = $('#og_value').val();
   actual_og = $('#og_actual').val();

   t2 = 1.34722124e-4*temp_val;
   t3 = 2.04052596e-6*temp_val*temp_val;
   t4 = 2.32820948e-9*temp_val*temp_val*temp_val;

   sgcf = 1.00130346 - t2 + t3 -t4
   sg = og_val * sgcf

   $('#og_actual').html(Math.round(sg * 100) / 100 +' %');

   OE = -668.962 + 1262.45*sg - 776.43*sg*sg + 182.94*sg*sg*sg
   $('#actual_oe').html(Math.round(OE * 100) / 100 +' %');

   max_alc = (sg -1) * 105 * 1.25;
   $('#max_alcohol').html(Math.round(max_alc * 100) / 100+' %');

});