Robot Speed Calculator

<script type="text/javascript"> // <![CDATA[

   $("input:enabled").change(function() {
           calcValues();
       });

       function calcValues () {
           var rpm = $("input[name='rpm']").val();
           var ratio = $("input[name='ratio']").val();
           var cir = $("input[name='diameter']").val() * Math.PI;

           var ipm = rpm * ratio * cir;
           var fpm = ipm / 12.0;
           var mph = fpm * 60 / 5280;
           var mpm = fpm * 0.3048;
           var kph = mpm * 60 / 1000;

           $("input[name='circ']").val(cir.toFixed(2));
           $("input[name='speedIPM']").val(ipm.toFixed(2));
           $("input[name='speedFPM']").val(fpm.toFixed(2));
           $("input[name='speedMPH']").val(mph.toFixed(2));
           $("input[name='speedMPM']").val(mpm.toFixed(2));
           $("input[name='speedKPH']").val(kph.toFixed(2));
       }

       $(function() {
           calcValues();
       });
   // ]]>
   </script>