We can find out memory usage of SQL Server by using below scripts.
select total_physical_memory_kb/1024 AS total_physical_memory_mb, available_physical_memory_kb/1024 AS available_physical_memory_mb, total_page_file_kb/1024 AS total_page_file_mb, available_page_file_kb/1024 AS available_page_file_mb, 100 - (100 * CAST(available_physical_memory_kb AS DECIMAL(18,3))/CAST(total_physical_memory_kb AS DECIMAL(18,3))) AS 'Percentage_Used', system_memory_state_desc from sys.dm_os_sys_memory;
After executing of above script we get the output like below:-
2. We can also use below query to find out memory usage of SQL server by using sys.dm_os_process_memory dmv.
select * from sys.dm_os_process_memory;
After execution of above we will get the output of memory usage in kb.