How can we identify used space in log file?

Many times we face this question in the interview “How can we identify used space in log file”.

 Using following DBCC command you can identify the used space in the log file.

DBCC SQLPERF('LOGSPACE')

Result:

You can see in result first column display DB name and second columns display total log file size in MB while the third column contains used size in MB which is our answer.