Crew in my company have to do their own calculations, however the companies rostering system of course has its own set of calculations including legal FTLs as well as our CLAs that deal with those issues. However, they often try to get around the CLA and just use the legal minimum required stuff.
There are a few FTL calculator apps out there, the ECA ones are nice for EASA FTL, many of us use EuOPSvsMTV which has the CLAs of quite a few airlines builtin as well.