They've got a 25% discount on this weekend - Advanced CNC Speed And Feed Calculator - HSMAdvisor
I've been using their FSwizard online version (FSWizard - Free Advanced CNC Speed and Feed Calculator), and their android version for a while, as it's nice and simple to use to get some ball park figures when in the workshop.
HSMadvisor is the PC based version and a bit more advanced, as it lets you configure more features (like set machine rpm/speed/power limits) so you can get even more accurate figures without having to manually juggle figures to keep within machine limits. You can also store tool/cut details for later reference (if you register for FSwizard online, you can store cutter details, but not cut details).
If you've not tried HSMadvisor, you can download and try it for free for 30days. And each time they release a new version, you get another 30 days, however with the offer, it's less than $55 for a single seat, so I think it's well worth buying.
(I've got no affiliation with the product, I just think it's one of the easiest to use feed and speed calculators with minimal hassle/configuration)
Avoiding the rubbish customer service from AluminiumWarehouse since July '13.