64 bit vs 32 bit?

I currently have a 32 bit version of Excel 2013 installed on my system. The majority of files I work with are not particularly large, however I find that even with a quad-core Intel i7 2.7 GHz with 8 GB RAM (64 bit OS), it seems to take rather long (sometimes >30 seconds) to calculate some of my sheets, even if I do menial tasks like deleting an unnecessary column (from a sheet with lots of formulae).

I've wondered about whether installing a 64 bit version of Excel might help, but from reading a bit about it, the consensus seems to be that 64 bit is only required if your Excel files are >2GB. Mine are probably less than 5 MB, but with heaps of lookup type formulae in it.

Any advice from someone who has some knowledge/experience about whether I am likely to see a substantial improvement in calculation time by installing the 64 bit version would be appreciated.

Cheers,
André