=TEXT(INT(DATEDIF([DOB],TODAY(),"D")/(12*29.530575)),"00")&" years "&
TEXT(INT(((DATEDIF([DOB],TODAY(),"D")/(12*29.530575)-INT(DATEDIF([DOB],TODAY(),"D")/(12*29.530575)))*12)),"00")&" months "&
TEXT(INT((((DATEDIF([DOB],TODAY(),"D")/(12*29.530575)-INT(DATEDIF([DOB],TODAY(),"D")/(12*29.530575)))*12)-INT(((DATEDIF([DOB],TODAY(),"D")/(12*29.530575)-INT(DATEDIF([DOB],TODAY(),"D")/(12*29.530575)))*12)))*29.530575),"00")&" days"