how to analyse different http request and response messages

I am analyzing different http request and response messages. I have got three different http request messages and i wana see at which time each of these messages are generated and how much bytes they consume? I can see number of bytes against each http request on clicking at any packet but i need some sort of automatic mechanism through which i am able to know number of bytes against different http request messages and same the case with the http response messages. Any help will be really appreciated