Classifying Naval Vessels By Tonnage? I have a question

[Neptune]

Okay I'm passing AAS's and AC's but Frigates and Destroyers? Sometimes even Cruisiers. I have two questions. 1- I have to know the ship classifying system of NATO and Russia (and it's allies). 2- there are some navies whom classify 1800-2000 tons as destroyer. But in our navy even 2500 tons TCG Heybeliada is a corvette. What is this about?

 

[Penguin]

A WW2 era destroyer might well be 2000 tons but today would count as not much more than a frigate.
Also, some nations like to inflate their naval capability by calling frigates (a.k.a. destroyer escorts) destroyers, while other navies seek to deflate their capability e.g. all the new Euro ´frigates´ of 6000+ ton (that could qualify as destroyer, particularly when AAW oriented').

See AMI International - Definitions of Vessel Types

I would say corvettes start around 800 tons an go up to 2000 tons, then you get ´light frigates´ e.g. Milgem, Type 053H3 and then general purpose frigates around 3-4000t, with AAW-frigates approaching 6000, and destroyers starting around 7-8000 and going up to 11000t, and cruisers starting 10000 going to 40000tons. Roughly

 

[Neptune]

Thank you for the information.