In order to properly create a useful bitcoin calculator, you need an Excel spreadsheet that has components like this:

example components

Put the price that you know of under the $ column.

put price

Label the months

label months

Click on the D column, under Difficulty + 10%, and place the same value you put beside the Current difficult in previous step, in this case it's (=B6)

Difficulty

Click under the result (1), type =D2+(D2*($B$7/100)), press enter (2), and double click on the small square (3).

Click under the result

Click under Coins/day (1), and type =$B$9*(86400/(D2*((2^32)/($B$2*1000000000)))) (2) and double click on small square (3). Note: 86400 is the seconds in a day.

Coins per day

Click under revenue/day (1), type =E2*$B$9 before pressing enter, and double click on the square (3).

revenue per day

Click under net/day (1), type =F2-($B$3*($B$4/1000)*24) then enter (2), and double click on the small square (3).

net per day

Click under Per month (H) column, type =SUMPRODUCT(--(G2-((G2-G3)/30)*ROW(INDIRECT(1&":"&30)))) (2) and double click on the small square (3).

Per month

Click empty cell in column G and write Net Annual (1), then beside it on (H) and type =SUM(H2:H13)-B6 and press enter (2)

Net Annual

Of course this BitCoin mining calculator is valid for AltCoins as well.

Good luck with your mining and HODL. Here you can download free BitCoin Mining Calculator.

Further reading:
How to calculate return on investment?
Loan amortization in Excel
Ethereum Network Difficulty
How to pull DeFi data to Excel?