var bills = [ { "refNo": 17, "billDate": "1-apr-2016", "dueDate": "30-apr-2016", "pendingAmount": 4500, "overdueDays": 28 }, { "refNo": 20, "billDate": "15-apr-2016", "dueDate": "3-may-2016", "pendingAmount": 56550, "overdueDays": 15 } ]; var res = bills.map(bill => bill.pendingAmount).reduce((acc, bill) => bill + acc); console.log(res)