function calculateAge() { var Bdate = document.getElementById('calculate_age').value; var Bday = new Date(Bdate); var today=Date.now(); var dateTo=new Date(today); var dateFrom=Bday; var Q4A = dateTo.getMonth() - dateFrom.getMonth() + (12 * (dateTo.getFullYear() - dateFrom.getFullYear())); var year = Math.floor(Q4A/12); var month = Q4A%12; $("#age").val(year + ' Year ' + month + ' Month '); }