I put together a debt repayment calculator tonight. You can download it here (link).
I’m sure there are infinite calculators available on the internet, but I enjoyed the modelling exercise.
Yellow cells are inputs. Grey cells are calculations.
I’m not really sure the demographics of this blog’s readers, but I suspect that most of you aren’t carrying around a lot of non-mortgage debt. If I’m wrong, perhaps this tool will be useful to you. If I’m right, perhaps this tool will be useful to someone you know. Or perhaps it will be useful to nobody.
I set up the sheet to accommodate up to 9 different loans. The key input parameters for each loan are (obliviously) the interest rate, minimum payment, and balance. This will work for any type of debt (credit card and/or student loan and/or car and/or mortgage). Put the highest interest loan on the left as “loan 1”, the next highest interest loan as “loan 2”, etc. If you have fewer than 9 loans, then zero out the extra loan balances in row 10.
Given total monthly debt payments (Cell E2), the sheet pays off the highest interest loans first (while making minimum payments on all other loans). Columns AC:AK compute the size of the extra payment in excess of the minimum payment.
Columns M&N (on the right side of the below image) show how soon in years until you’re debt free at a given monthly repayment amount.
If you wanted to make extra payments in a given month (in excess of the baseline repayment in cell E2), you can input that manually in columns AC:AK.
It’s a lot more fun to earn interest than to pay interest, but before you earn interest it is helpful to get out of high-interest debt first.