I know if a game is calculated as being over 25 mins using the formula: mins*60 + increment*40 it becomes classical rather than rapid

What is the formula for the blitz vs rapid cut-off?

Ignore this, I've found the answer: 8 mins (per side)

8+0 is rapid, so prolly 7.

I've seen a tournament in Zagreb few months back and they played blitz 10 minutes, and I'm not sure but I think they had 5 seconds delay as well. I think on this site everything is narrowed down.

The formula used is: (mins*60 + increment*40)/60

If the answer is

3 and over* it is blitz,

8 and over it's rapid

25 and over it's classical

* over in this sense means up to the next threshold. So 3 to 7.9999999... etc