I originally calculated how much interest I was paying to finance companies and banks in 2009.  Re-reading the post I actually remember feeling very annoyed how much money was being spent just servicing my debt.  While I updated the numbers some 19 months later, I haven’t looked into these calculations in over 4 years.

Calculating Monthly Interest Paid on my Debt

Below is what my debt servicing looked in 2011 (as compared to 2009):

DebtMonthly PaymentPrincipal PortionInterest PortionDifference From 19 Months Ago
Mortgage Payment$1,259 (without Taxes)$183$1076$44 More towards Principal
Student Loan #1$252$82$170$82 More Towards Principal
Student Loan #2$106$80$26$5 More Towards Principal
Auto Loan*$221$198$22$92 Will be paid off by the End of the Month
Total$1838$543$1,294$204 Less Interest Per Month


Wow things have changed since that post was written! My 4 year old boy was about the same age as my 6 month old daughter is currently.  Focusing on monetary changes:

  • The auto loan was paid off years ago
  • Student Loan #2 was paid off
  • The mortgage is much larger

Current debt servicing:

Mortgage Payment$1,047
Student Loan #1$140

So the total is a couple hundred less than a few years ago.

Two interesting things came from this exercise.  One, despite the mortgage being larger the interest payment is actually lower because of the reduction in interest rates.  Two, the student loan ratcheted up at some point between today and that post so the payment is actually higher (from $252 to $334/mo).  So, it means even more is going towards principal today.  Both of these are 30 year notes at fixed terms below 4% so this doesn’t seem like an exercise I would undertake again in the near future.


Have you ever actually calculated this number? It has to be even more infuriating if you have non-0% credit cards.