Total size of an S3 bucket

s3cmd tool is used to get size of bucket or folder:

$ s3cmd du s3://my-bucket-name
74117816147

$ s3cmd du s3://my-bucket-name/folder
$ s3cmd du s3://my-bucket-name/folder/subfolder
$ s3cmd -c ~/.s3cfg du s3://my-bucket-name

To get human readable size on s3cmd we should add option: -H or --human-readable-sizes:

-H, --human-readable-sizes :
Print sizes in human readable form (eg 1kB instead of 1234 or MB, GB, TB).

$ s3cmd du -H s3://my-bucket-name
69GB