You calculate your net worth by preparing a balance sheet. Your net worth is the sum of your assets minus the sum of your liabilities, which are listed on your balance sheet. Your net worth and balance sheet are snapshots in time and do not directly reflect your monthly income and expenses.
First, list all of your financial assets by type and amount. Financial assets might include the money in your checking and savings accounts, investments, your home, your car, other valuable property, etc.
Second, list all of your financial liabilities or debts by type and outstanding balance. Your liabilities may include student loans, your credit card balance(s), your mortgage, your car loan, personal loans, etc.
Third, subtract the sum of your liabilities from the sum of your assets. This number is your net worth.
It is useful to track your net worth so that you can see how it changes with time. While some financial software may report your net worth daily, to make fair comparisons, it is most useful to update your balance sheet and net worth on a monthly, quarterly, or yearly basis.
Resource: What is my current net worth?