How degree classification works

If second year counts for 25% and third year 75% how would it work in terms of grades I would need. Say if I wanted a 2:2, would that mean I would be alright getting 50-59% in second year modules, but would need a higher mark in third year modules?
It doesn’t quite work like that exactly. If you want to know the way to calculate it:

Take what you got in your 2nd year, or what you think you are on track to get. To keep it simple we will say 55.

For 3rd year, let’s say you get 65 (or in other words a 2.1 for that year)

(0.25 * 55) + (0.75 * 65)

= 62.5

Meaning this would actually get you a 2.1 overall

However, let’s say you don’t do as well in the third year and you get 45.

(0.25 * 55) + (0.75 * 45)

= 47.5

So this would actually give you a 3rd or a pass overall.

The way I think of it is, you really want to make sure you aren’t having any absolute howlers in year 3 because that will impact your overall a lot.

You can play around with this calculation or just use an online uni grade calculator lol.

Hope this helps.