HTTP header response data

I want to calculate the size in bytes 开发者_StackOverflow社区of the http response headers and data in PHP. Any help would be appreciated

You can't measure the size of the response headers from your PHP code because the webserver may change them before serving them up. Only the webserver can measure this - and you don't say what webserver you are using. With Apache, install mod_logio and start recording %I, %O and %B