Compare loading time of your competition
To define your own requirements related to loading times it obviously helps to know what competition does. As a general guideline: New Relic showed in May 2011 that pages around the world load in average 6 seconds. Our own research showed that the top 100 largest sites of the Netherlands load in 2.6 seconds.
While we are preparing extensive benchmark reports on site loading times per branch, we hope you don’t mind checking your main competitors yourself via pingdom, webpagetest or some other free measurement tool in the meantime. Yottaa built some fancy way of comparing loading time of competitors over time.
Of course you can also use SpeedProfs Global Performance Test to get a quick understanding as well.
Also http://www.speedoftheweb.org/ from DynaTrace has some nice benchmarking on their site too.