Google Webmaster Central relaunched the Page Speed tool, an easy to way find how fast your website loads. The new feature is that now you can also test mobile version of your website. At the end you get suggestions on how you can speed up further.
However when I checked our blog on PageSpeed most of the problem that showed up was for external websites i.e. Ad Networks, Google Translate. So if you want to actually find issues just related with your website, create a sample page with but of content and all things that appear on your website except external resources and you will know. Check Page Speed Tool| Thanks Matt Cutts