<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css"> <script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script> <script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script> <!------ Include the above in your HEAD tag ----------> <div class="col-md-12"> <div class="col-md-4"> <div class="col-md-4" id="padding6"> <label>Tenure</label> <select class="form-control year" id="select61"> <option value="0">0 Year</option> <option value="1">1 Year</option> <option value="2">2 Year</option> <option value="3">3 Year</option> <option value="4">4 Year</option> <option value="5">5 Year</option> </select> </div> <div class="col-md-5" id="padding62"> <select class="form-control month" id="select62"> <option value="0">0 Month</option> <option value="1">1 Month</option> <option value="2">2 Month</option> <option value="3">3 Month</option> <option value="4">4 Month</option> <option value="5">5 Month</option> <option value="6">6 Month</option> <option value="7">7 Month</option> <option value="8">8 Month</option> <option value="9">9 Month</option> <option value="10">10 Month</option> <option value="11">11 Month</option> <option value="12">12 Month</option> </select> </div> <div class="col-md-3" id="padding63"> <input type="text" style="font-size:10px;padding: 8px;" class="select62 form-control tdays " name="" id="select62"> </div> </div> </div>

#padding6{ padding: 0px; } #padding63{ padding-top: 29px; padding-left: 0px; } #padding62{ padding-top: 29px; padding-left: 0px; padding-right: 0px; } #select62{ border-left: 0px; border-radius: 0px; } #select61{ border-right: 0px; border-radius: 0px; } .select62{ padding: 8px; font-size: 10px; font-weight: 800; }

$('.year').on('change',function(){ var year=this.value; var month=$('.month').val(); var onemonth='30'; var totalmonth=month*onemonth; var oneyear='365'; var totaldays=year*oneyear; var monthyear=parseInt(totalmonth)+parseInt(totaldays); $('.tdays').val(monthyear); }) $('.month').on('change',function(){ var month=this.value; var year=$('.year').val(); var onemonth='30'; var oneyear='365'; var totalmonth=month*onemonth; var totalyear=year*oneyear; var monthyear=parseInt(totalmonth)+parseInt(totalyear); $('.tdays').val(monthyear); })