SELECT
  table_schema "db.name"
, Round(Sum(data_length + index_length) / 1024 / 1024, 1) "DB Size in MB"
FROM
  information_schema.tables
GROUP BY
  table_schema;

SELECT data_length+index_length tblsize
FROM information_schema.tables
WHERE table_schema='mydb' AND table_name='mytable';

DB=mydb
TB=mytable
cd /var/lib/mysql/${DB}
TBL_OSBYTES=0
for X in `ls -l ${TB}.[iM][bY][dDI] | awk '{print $9}' ; do (( TBL_OSBYTES += X )) ; done

MYSQL_USER=root
MYSQL_PASS=rootpassword
MYSQL_CONN="-u${MYSQL_PASS} -p${MYSQL_PASS}"
DB=mydb
TB=mytable
cd /var/lib/mysql/${DB}
TBL_PHYBYTES=0
for X in `ls -l ${TB}.[iM][bY][dDI] | awk '{print $9}' ; do (( TBL_OSBYTES += X )) ; done
SQL="SELECT data_length+index_length"
SQL="${SQL} FROM information_schema.tables"
SQL="${SQL} WHERE table_schema='${DB}' AND table_name='${TB}'";
TBL_LOGBYTES=`mysql ${MYSQL_CONN} -ANe"${SQL}"`
(( TBL_FRGBYTES = TBL_PHYBYTES - TBL_LOGBYTES ))
echo "Table Stats for ${DB}.${TB}"
echo "Physical Size : ${TBL_PHYBYTES}"
echo "Logical Bytes : ${TBL_LOGBYTES}"
echo "Fragmentation : ${TBL_FRGBYTES}"

MYSQL_USER=root
MYSQL_PASS=rootpassword
MYSQL_CONN="-u${MYSQL_PASS} -p${MYSQL_PASS}"
DB=mydb
cd /var/lib/mysql/${DB}
TBL_PHYBYTES=0
for X in `ls -l *.[iM][bY][dDI] | awk '{print $9}' ; do (( TBL_OSBYTES += X )) ; done
SQL="SELECT data_length+index_length"
SQL="${SQL} FROM information_schema.tables"
SQL="${SQL} WHERE table_schema='${DB}'";
TBL_LOGBYTES=`mysql ${MYSQL_CONN} -ANe"${SQL}"`
(( TBL_FRGBYTES = TBL_PHYBYTES - TBL_LOGBYTES ))
echo "Table Stats for ${DB}.${TB}"
echo "Physical Size : ${TBL_PHYBYTES}"
echo "Logical Bytes : ${TBL_LOGBYTES}"
echo "Fragmentation : ${TBL_FRGBYTES}"

MYSQL_USER=root
MYSQL_PASS=rootpassword
MYSQL_CONN="-u${MYSQL_PASS} -p${MYSQL_PASS}"
SQL="SELECT schema_name FROM information_schema.schemata"
SQL="${SQL} WHERE schema_name NOT IN ('information_schema','mysql','performance_schema')";
DBLIST=""
for DB in `mysql ${MYSQL_CONN} -ANe"${SQL}"` ; do DBLIST="#{DBLIST} ${DB}" ; done
TBL_PHYBYTES=0
for DB in `echo "${DBLIST}"`
do
    cd /var/lib/mysql/${DB}
    for X in `ls -l *.[iM][bY][dDI] | awk '{print $9}' ; do (( TBL_OSBYTES += X )) ; done
done
SQL="SELECT data_length+index_length"
SQL="${SQL} FROM information_schema.tables"
SQL="${SQL} WHERE table_schema NOT IN ('information_schema','mysql','performance_schema')";
TBL_LOGBYTES=`mysql ${MYSQL_CONN} -ANe"${SQL}"`
(( TBL_FRGBYTES = TBL_PHYBYTES - TBL_LOGBYTES ))
echo "Table Stats for ${DB}.${TB}"
echo "Physical Size : ${TBL_PHYBYTES}"
echo "Logical Bytes : ${TBL_LOGBYTES}"
echo "Fragmentation : ${TBL_FRGBYTES}"