MySQL Workbench Database Sizes
I have some queries you can run against the INFORMATION_SCHEMA

Run this to get the Total MySQL Data and Index Usage By Storage Engine

SELECT IFNULL(B.engine,'Total') "Storage Engine",
CONCAT(LPAD(REPLACE(FORMAT(B.DSize/POWER(1024,pw),3),',',''),17,' '),' ',
SUBSTR(' KMGTP',pw+1,1),'B') "Data Size", CONCAT(LPAD(REPLACE(
FORMAT(B.ISize/POWER(1024,pw),3),',',''),17,' '),' ',
SUBSTR(' KMGTP',pw+1,1),'B') "Index Size", CONCAT(LPAD(REPLACE(
FORMAT(B.TSize/POWER(1024,pw),3),',',''),17,' '),' ',
SUBSTR(' KMGTP',pw+1,1),'B') "Table Size" FROM
(SELECT engine,SUM(data_length) DSize,SUM(index_length) ISize,
SUM(data_length+index_length) TSize FROM
information_schema.tables WHERE table_schema NOT IN
('mysql','information_schema','performance_schema') AND
engine IS NOT NULL GROUP BY engine WITH ROLLUP) B,
(SELECT 3 pw) A ORDER BY TSize;


Run this to get the Total MySQL Data and Index Usage By Database

SELECT DBName,CONCAT(LPAD(FORMAT(SDSize/POWER(1024,pw),3),17,' '),' ',
SUBSTR(' KMGTP',pw+1,1),'B') "Data Size",CONCAT(LPAD(
FORMAT(SXSize/POWER(1024,pw),3),17,' '),' ',SUBSTR(' KMGTP',pw+1,1),'B') "Index Size",
CONCAT(LPAD(FORMAT(STSize/POWER(1024,pw),3),17,' '),' ',
SUBSTR(' KMGTP',pw+1,1),'B') "Total Size" FROM
(SELECT IFNULL(DB,'All Databases') DBName,SUM(DSize) SDSize,SUM(XSize) SXSize,
SUM(TSize) STSize FROM (SELECT table_schema DB,data_length DSize,
index_length XSize,data_length+index_length TSize FROM information_schema.tables
WHERE table_schema NOT IN ('mysql','information_schema','performance_schema')) AAA
GROUP BY DB WITH ROLLUP) AA,(SELECT 3 pw) BB ORDER BY (SDSize+SXSize);


Run this to get the Total MySQL Data and Index Usage By Database and Storage Engine

SELECT Statistic,DataSize "Data Size",IndexSize "Index Size",TableSize "Table Size"
FROM (SELECT IF(ISNULL(table_schema)=1,10,0) schema_score,
IF(ISNULL(engine)=1,10,0) engine_score,
IF(ISNULL(table_schema)=1,'ZZZZZZZZZZZZZZZZ',table_schema) schemaname,
IF(ISNULL(B.table_schema)+ISNULL(B.engine)=2,"Storage for All Databases",
IF(ISNULL(B.table_schema)+ISNULL(B.engine)=1,
CONCAT("Storage for ",B.table_schema),
CONCAT(B.engine," Tables for ",B.table_schema))) Statistic,
CONCAT(LPAD(REPLACE(FORMAT(B.DSize/POWER(1024,pw),3),',',''),17,' '),' ',
SUBSTR(' KMGTP',pw+1,1),'B') DataSize,CONCAT(LPAD(REPLACE(
FORMAT(B.ISize/POWER(1024,pw),3),',',''),17,' '),' ',
SUBSTR(' KMGTP',pw+1,1),'B') IndexSize,
CONCAT(LPAD(REPLACE(FORMAT(B.TSize/POWER(1024,pw),3),',',''),17,' '),' ',
SUBSTR(' KMGTP',pw+1,1),'B') TableSize FROM (SELECT table_schema,engine,
SUM(data_length) DSize,SUM(index_length) ISize,
SUM(data_length+index_length) TSize FROM information_schema.tables
WHERE table_schema NOT IN ('mysql','information_schema','performance_schema')
AND engine IS NOT NULL GROUP BY table_schema,engine WITH ROLLUP) B,
(SELECT 3 pw) A) AA ORDER BY schemaname,schema_score,engine_score;


CAVEAT

In each query, you will see (SELECT 3 pw). The pw stands for the Power Of 1024 to display the results.


(SELECT 0 pw) will Display the Report in Bytes
(SELECT 1 pw) will Display the Report in KiloBytes
(SELECT 2 pw) will Display the Report in MegaBytes
(SELECT 3 pw) will Display the Report in GigaBytes
(SELECT 4 pw) will Display the Report in TeraBytes
(SELECT 5 pw) will Display the Report in PetaBytes (please contact me if you run this one)


Here is a report query with a little less formatting:

SELECT IFNULL(db,'Total') "Database",
datsum / power(1024,pw) "Data Size",
ndxsum / power(1024,pw) "Index Size",
totsum / power(1024,pw) "Total"
FROM (SELECT db,SUM(dat) datsum,SUM(ndx) ndxsum,SUM(dat+ndx) totsum
FROM (SELECT table_schema db,data_length dat,index_length ndx
FROM information_schema.tables WHERE engine IS NOT NULL
AND table_schema NOT IN ('information_schema','mysql')) AA
GROUP BY db WITH ROLLUP) A,(SELECT 1 pw) B;


Give it a Try !!!

UPDATE 

I just ran the first query as is on a client's DB

mysql&gt; SELECT IFNULL(B.engine,'Total') "Storage Engine",
    -&gt; CONCAT(LPAD(REPLACE(FORMAT(B.DSize/POWER(1024,pw),3),',',''),17,' '),' ',
    -&gt; SUBSTR(' KMGTP',pw+1,1),'B') "Data Size", CONCAT(LPAD(REPLACE(
    -&gt; FORMAT(B.ISize/POWER(1024,pw),3),',',''),17,' '),' ',
    -&gt; SUBSTR(' KMGTP',pw+1,1),'B') "Index Size", CONCAT(LPAD(REPLACE(
    -&gt; FORMAT(B.TSize/POWER(1024,pw),3),',',''),17,' '),' ',
    -&gt; SUBSTR(' KMGTP',pw+1,1),'B') "Table Size" FROM
    -&gt; (SELECT engine,SUM(data_length) DSize,SUM(index_length) ISize,
    -&gt; SUM(data_length+index_length) TSize FROM
    -&gt; information_schema.tables WHERE table_schema NOT IN
    -&gt; ('mysql','information_schema','performance_schema') AND
    -&gt; engine IS NOT NULL GROUP BY engine WITH ROLLUP) B,
    -&gt; (SELECT 3 pw) A ORDER BY TSize;
+----------------+----------------------+----------------------+----------------------+
| Storage Engine | Data Size            | Index Size           | Table Size           |
+----------------+----------------------+----------------------+----------------------+
| MyISAM         |             0.673 GB |             0.079 GB |             0.752 GB |
| InnoDB         |             4.227 GB |             2.436 GB |             6.663 GB |
| Total          |             4.900 GB |             2.515 GB |             7.415 GB |
+----------------+----------------------+----------------------+----------------------+
3 rows in set (0.79 sec)

mysql&gt;


It works as is.

UPDATE 2015-01-16 14:46 EST

Here are Queries to Report Sizes and Computes the Memory Units On-The-Fly

Total MySQL Data and Index Usage By Storage Engine

SELECT IFNULL(ENGINE,'Total') "Storage Engine",
LPAD(CONCAT(FORMAT(DAT/POWER(1024,pw1),2),' ',
SUBSTR(units,pw1*2+1,2)),17,' ') "Data Size",
LPAD(CONCAT(FORMAT(NDX/POWER(1024,pw2),2),' ',
SUBSTR(units,pw2*2+1,2)),17,' ') "Index Size",
LPAD(CONCAT(FORMAT(TBL/POWER(1024,pw3),2),' ',
SUBSTR(units,pw3*2+1,2)),17,' ') "Total Size" FROM
(SELECT ENGINE,DAT,NDX,TBL,IF(px&gt;4,4,px) pw1,
IF(py&gt;4,4,py) pw2,IF(pz&gt;4,4,pz) pw3 FROM
(SELECT *,FLOOR(LOG(IF(DAT=0,1,DAT))/LOG(1024)) px,
FLOOR(LOG(IF(NDX=0,1,NDX))/LOG(1024)) py,
FLOOR(LOG(IF(TBL=0,1,TBL))/LOG(1024)) pz
FROM (SELECT ENGINE,SUM(data_length) DAT,SUM(index_length) NDX,
SUM(data_length+index_length) TBL FROM (SELECT engine,data_length,index_length
FROM information_schema.tables WHERE table_schema NOT IN
('information_schema','performance_schema','mysql') AND ENGINE IS NOT NULL) AAA
GROUP BY ENGINE WITH ROLLUP) AAA ) AA) A,(SELECT ' BKBMBGBTB' units) B;


Total MySQL Data and Index Usage By Database

SELECT IFNULL(DB,'Total') "Database",
LPAD(CONCAT(FORMAT(DAT/POWER(1024,pw1),2),' ',
SUBSTR(units,pw1*2+1,2)),17,' ') "Data Size",
LPAD(CONCAT(FORMAT(NDX/POWER(1024,pw2),2),' ',
SUBSTR(units,pw2*2+1,2)),17,' ') "Index Size",
LPAD(CONCAT(FORMAT(TBL/POWER(1024,pw3),2),' ',
SUBSTR(units,pw3*2+1,2)),17,' ') "Total Size"
FROM (SELECT DB,DAT,NDX,TBL,IF(px&gt;4,4,px) pw1,
IF(py&gt;4,4,py) pw2,IF(pz&gt;4,4,pz) pw3 FROM
(SELECT *,FLOOR(LOG(IF(DAT=0,1,DAT))/LOG(1024)) px,
FLOOR(LOG(IF(NDX=0,1,NDX))/LOG(1024)) py,
FLOOR(LOG(IF(TBL=0,1,TBL))/LOG(1024)) pz
FROM (SELECT DB,SUM(data_length) DAT,SUM(index_length) NDX,
SUM(data_length+index_length) TBL FROM
(SELECT table_schema DB,data_length,index_length FROM information_schema.tables
WHERE table_schema NOT IN ('information_schema','performance_schema','mysql')
AND ENGINE IS NOT NULL) AAA GROUP BY DB WITH ROLLUP) AAA) AA) A,
(SELECT ' BKBMBGBTB' units) B;


Total MySQL Data and Index Usage By Database/Storage Engine

SELECT IF(ISNULL(DB)+ISNULL(ENGINE)=2,'Database Total',
CONCAT(DB,' ',IFNULL(ENGINE,'Total'))) "Reported Statistic",
LPAD(CONCAT(FORMAT(DAT/POWER(1024,pw1),2),' ',
SUBSTR(units,pw1*2+1,2)),17,' ') "Data Size",
LPAD(CONCAT(FORMAT(NDX/POWER(1024,pw2),2),' ',
SUBSTR(units,pw2*2+1,2)),17,' ') "Index Size",
LPAD(CONCAT(FORMAT(TBL/POWER(1024,pw3),2),' ',
SUBSTR(units,pw3*2+1,2)),17,' ') "Total Size" FROM
(SELECT DB,ENGINE,DAT,NDX,TBL,
IF(px&gt;4,4,px) pw1,IF(py&gt;4,4,py) pw2,IF(pz&gt;4,4,pz) pw3 FROM
(SELECT *,FLOOR(LOG(IF(DAT=0,1,DAT))/LOG(1024)) px,
FLOOR(LOG(IF(NDX=0,1,NDX))/LOG(1024)) py,
FLOOR(LOG(IF(TBL=0,1,TBL))/LOG(1024)) pz
FROM (SELECT DB,ENGINE,SUM(data_length) DAT,SUM(index_length) NDX,
SUM(data_length+index_length) TBL FROM (SELECT table_schema DB,ENGINE,
data_length,index_length FROM information_schema.tables WHERE table_schema NOT IN
('information_schema','performance_schema','mysql') AND ENGINE IS NOT NULL) AAA
GROUP BY DB,ENGINE WITH ROLLUP) AAA) AA) A,(SELECT ' BKBMBGBTB' units) B;