There is no calculator that I know of. I can get you consultants that really know about big SuiteCRM installations if you want and are willing to hire. That's probably the wisest route, if you are in charge of a big installation.
If you just want to keep asking in the Forums I don't mind helping out for free, of course, tell me a bit more about your planned architecture (will you bw splitting database and web server, using load balancing, etc?)
My SuiteCRM In-depth blog. Thank you for always stating your SuiteCRM version, checking your logs, reading the Docs, and searching before you ask!
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