Time signatures and beat calculations

[Drammy]

Right, I have some gaps in my musical knowledge and I am hoping someone can fill them for me...

With time signatures I know that 4/4 means there are 4 instances of a 1/4 note per measure.

So 5/8 would mean that there are 5 instances of an 1/8 note per measure.

My question is this - does that mean that with a 5/8 time signature there are 5 beats per measure?

So with a tempo of 100bpm and a time signature of 5/8, is the following maths correct:

300ms per 1/8 note (ie beat)

and 1.5s per measure

I think I have but would appreciate someone confirming this or if not then explaining it in simpleton terms.

Thanks,

Drammy