Hi Cherrie,
Please just call me Peter.....
Now, to your question....If this is in support of 'adequate maintenance' due to exemption from Financial Requirements then I'd very kindly suggest you follow the UKVI method for setting out a calculation which is :-
A – B ≥ C
Where:-
A is the total income (after deduction of any tax and NI contributions)
B is total costs of housing (after deduction of rent & council tax)
C is the amount of Income Support an equivalent British family of the same size can receive
Once you begin to transpose formulae and present differently from that which UKVI are expecting you run the risk of causing confusion and potential delays or errors on the part of the ECO and/or caseworkers.
Avoid averaging of income and don't include bills. Just follow the UKVI calculation.
You need to arrive at an amount which is equal to or greater than Income Support which is currently £113.70 for a couple over 18
If you can't meet that Income Support amount any application may fall for refusal.
Hope that helps to clarify