Degree classification help please

Hey, Guys need some help please - I have an amazing postgrad job offer and its conditioned on me getting a 2.1. Can someone help me figure it out as I'm attending a lot of training days and don't want to get my hopes up.
This is how my uni works it out (I've tried a lot of calculators and they don't work as they weight year 2/3 differently.

20% diss level 6 -30 credits
40 % average of the best 60 credits at level 6
40% average of the best 120 credits level 5/6

All modules are worth 15 credits apart from diss worth 30 credits)

Year 2 grades
57, 58, 58, 59, 60, 60, 63, 64

Year 3
Diss - 60 (estimated)
63, 65, 72, 60, 60, 60 (last three estimated)

There's a chance i will get higher than 60 on my last three modules but playing it safe.

Can someone calculate or tell me how to if these were my grades and if i got a 55 in my dissertation. Thankyou!! Also ii think the way its worked out the worst two module grades are automatically dropped.

Many Thanks in advance!!

Tbh your explanation of how your uni classifies degrees looks odd. Which uni is it?

In any case, if you achieve your guesstimated marks you will get a 2.1.

Thanks for your response

I know its bizarre! Its Winchester university, I'm hoping my dissertation grade doesn't ruin the overall classification - I cant see me getting under a 55 but who knows!

I've found your regulations and understand them now - you missed out the word "remaining" from the sentence about the best 120 credits.

If you get 60 in your diss and in the other 3 unmarked modules then you will end up with 62.2. Even 55 in your diss only brings it down to 61.2.

Also have a look at section F4 of you Academic Regulations for Taught Programmes. You might need to get 60 via the alternative route.

With those grade estimates:
20% - 60
40% - 65
40% - 61.75
Gives 62.7% overall

With diss at 55 gives 61.7% overall