How can i learn flac filesize with reading flac header, i do not want to download all file to learn file size ? I can read samplerate and totalsamples count

Thanks

Where are you downloading from?
If it is a ftp site, you can just list the directory or you can use a GUI ftp client.
If it is a web page, you can use some download manager/accelerator, it will show you the file size as well as the estimated time.

Edit: Sorry, I didn't see your later post.

I am reading file from internet with visual basic code, can i calculate filesize with reading file header ?

Impossible from file header. However, you might be able to make an estimate.

For http download, you can parse the http header "Content-length", which will contain the filesize.