// Animate the element's value from x to y: $({someValue: 40000}).animate({someValue: 45000}, { duration: 3000, easing:'swing', // can be anything step: function() { // called on every step // Update the element's text with rounded-up value: $('#el').text(commaSeparateNumber(Math.round(this.someValue))); } }); function commaSeparateNumber(val){ while (/(\d+)(\d{3})/.test(val.toString())){ val = val.toString().replace(/(\d)(?=(\d\d\d)+(?!\d))/g, "$1,"); } return val; }