I did a search on "load speed for my url" and found a bunch of tools, none of which do what you want. However, you can use any of them to find the total size of your page(s) and then plug them into this tool:

http://www.csgnetwork.com/csdlspeedcalc.html

That one gives you load times for all the connection speeds for a particular size of download. I searched for "load time vs. connection speed".

Kind of an around the barn approach, but should give you what you need.