Determining size of MySQL DB dump and individual tables before dumping it

per_table.sql

SELECT
  TABLE_SCHEMA,
  TABLE_NAME,
  DATA_LENGTH / POWER(1024,1) Data_KB,
  DATA_LENGTH / POWER(1024,2) Data_MB,
  DATA_LENGTH / POWER(1024,3) Data_GB
FROM information_schema.tables WHERE table_schema NOT IN ('information_schema','performance_schema','mysql') ORDER BY DATA_LENGTH;

whole_database.sql

SELECT
    Data_BB / POWER(1024,1) Data_KB,
    Data_BB / POWER(1024,2) Data_MB,
    Data_BB / POWER(1024,3) Data_GB
FROM (SELECT SUM(data_length) Data_BB FROM information_schema.tables
WHERE table_schema NOT IN ('information_schema','performance_schema','mysql')) A;