how do i caluclate retained earnings

hello,
computation of retained earnings is easy and simple but first of all you need to understand the basics.
meaning: retained means we have kept something aside and right now not making use of such particular earnings.

thus now, when one arrives at the figure of PBT

i.e. PBT(Profit before taxes)

less: Taxes paid / provision for taxes made

you get PAT(profit after taxes)
less : any preference dividend including equity dividend also including any taxes thereof
less: any other appropriation of profits to reserves or whatever name called

thus balance is the profit called your RETAINED EARNINGS which you reserve for the future growth of the business.

Calculate retained earnings based on what information? Different problems present different types of information, so there isn't any definative answer without knowing what info you've been given.

any preference dividend including equity dividend also including any taxes thereof

?? Taxes on dividends paid??

Beginning R.E. earingins October 1, 20xx .....$XX
Add: Net income or <Net Loss> ..................$XX


Less: Dividends .........................................$XX
Ending R.E. earnings October 31, 20xx .........$XX