Operating profit variance

Hello, please can you let me know what is the correct calculation of operating profit variance % change against budget and prior year- to the same period eg.

YTD 30/09/2020
ACTUAL_ BUDGET_____PRIOR YEAR

(OP.Profit) 55000 __8000 ________104000

CHANGE AGAINST
BUDGET____PRIOR YEAR
x% ________x%

With the budget do we compare Budget to Actual (Budgeted- Actual/Budgeted)?
Eg.
BUDGETED (8K) to ACTUAL (55K)- So budgeted was £8000 less actual £55000= (47000)/ budgeted 8000 x 100% = -587.50% – I know is Favourable Variance but why is the % minus? Should I do ACTUAL- BUDGETED/BUDGETED instead?

With the change against prior year, do we compare Prior Year £104000 to Actual £55000= (104000-55000)/104000 x 100= 47.11% – I know it’s ADVERSE VARIANCE because op profit was higher last year that is now but don’t understand why is positive % not minus? Should it be Actual- Prior Year/Prior Year?
I appreciate your help, thank you!