If one pays khums every week from his weekly salary, then he does not have to pay khums at end of the khums year. If he did not do so, as he is permitted to delay the payment of khums until the end of the khums year, then he can pay the khums from the remainder of his earnings after the payment of the yearly expenses.

It is obligatory on every duty-bound individual to determine a khums fiscal year and calculate the remaining money after covering his expenses and pay the fifth of the remainder.

With the assumption that you paid khums on the capital money before you used it for the business, at the end of the khums year the debts and all other paid expenses for that year are deducted from the profits, and khums is due on the remaining balance. If the balance is zero or negative, no khums is due for that year.

Your net wealth is $1000, whereas $800 is the 80% of last year’s net income after khums was paid. This means that your net income for this year is $200 from which you have to pay khums ($40). Therefore, for the next year $960 will be exempted from khums ($800 from the previous year, plus $160 remaining from the current year).

If the salary payments are deposited in an account in a private or government bank, then it is subject to khums. This also applies to a transfer of the salary payments to an account in a private bank.
If the salary payments are transferred into an account in a government bank, then it not considered owned until it is withdrawn physically and khums is not due before that.
It is obligatory to pay khums at the end of the khums year from what remains after any expenses paid.

You can calculate the khums of the amount in the bank account by calculating 20% of the remaining balance.

If you did not live in the house until after the end of the khums year, then the khums is the fifth of the house’s value. If you lived in the house before the end of the khums year, then the house is not a subject to khums. You should pay khums from your savings and the unused gold.

Yes, this is true; you should determine the beginning of the Khums year, which is a set date ever year. For the past period in which the Khums has not been paid, you will need to agree with your Marja or his agent on an appropriate set date and to calculate the due Khums accordingly.
Additional to this, you will need to pay the Khums of all unused items in your possession, include money you have in your hands as cash and what you have saved in the bank.
Once the due Khums has been paid, you are left with 80% of the original amount. Khums will not be paid on this 80% remainder again, and you are to calculate the next Khums payment on any further savings at the next set date.

If you have debts from this present year that remained unpaid at the end of the khums fiscal year, and they are more than the net profit of this current year, then you do not have to pay khums.

If one took a loan for the purposes of spending it for the current year’s expenses, the outstanding balance of the loan at the end of the khums year can be deducted from the total savings. If the debt is greater than all the savings from that year, then there is no khums to pay. If not, the difference is subject to khums.

Khums is payable on those items which have remained unused until the end of the khums year. The amount payable is based on the value at the end of the khums year.

Yes, the unspent savings and monies at the end of the khums year should be considered, whether that money was with you throughout the whole year or you just received it.

Yes, one should pay khums on the savings deducting the amount of the unpaid loan, if the borrowed money was spent to cover the expenses of the past year and not for that of previous years. However, if the loan was spent on expenses of previous years then it should not be deducted.

You should pay the khums on the amount that you do not have access to once you do gain access to it.

The beginning of the khums year is the day one makes a profit, even when he was a child. Based on this, it does not matter when you started your work.
Since you do not know this day, you should set the khums year by reconciliation (Musalahah) with the Marja or his agent.

The khums is payable based on its value on the day khums becomes applicable on it.

There is no khums on the money from which khums was already paid, i.e. the 32,000 Rubles (which is 40,000 minus 8,000 khums). So khums will be paid from 118,000 (which is 150,000 minus 32,000).

If the beginning of Muharram is the first day of your khums fiscal year then khums is payable at the end of Dhil-Hijjah, even if you started saving in Dhil-Qa’dah and did not save anything before that.
The khums fiscal year begins when one gains any money in his life, even when he was a child. If you know that day then this is when you pay khums on any profit that remains unspent, even if you received the money days before this date. If you do not know that day exactly, then you should refer to the religious authority, i.e. the marja that you follow or his agents, to determine a day to be the start of your khums fiscal year.

It is sufficient to pay the fifth in your case.

If a loan is taken within this khums fiscal year, it can be deducted from the savings of that same year. If the loan was taken in an earlier year, it cannot be deducted from the savings of this year.