Assuming there is no fees on paying extra $10k at the time of the first scheduled mortgage payment, what would be better - to put this $10k towards a downpayment or make bigger regular payment?

Maybe someone can show me online calculator where I can calculate the difference at the end?


This calculator will let you calculate the savings from making a prepayment right away. Run it twice: once with a smaller initial balance, and once with the high balance and the prepayment.

If you add the extra $10k to your down payment, your monthly payment will be lower. The higher monthly payment you will have with the $10k in your first payment means that you'll be paying more principal every month, right from the beginning.

Using the calculator above with a $200k mortgage at 5% fixed for 30y: if you use the $10k as a prepayment, you'll save about $22k in interest over the life of the loan, which will be shortened by 38 months. Bottom line: don't put it into the down payment. But also see KeithB's answer for the trade-off here.

That's assuming a US mortgage, which is different from Canada. I ran the same numbers using this calculator from RBC and came up roughly the same amount. (I find the first calculator above much easier to use, if you aren't worried about losing a little precision in the numbers.)

  • Thanks, so which way is better? :) – serg Mar 31 '11 at 17:47
  • @serg: sorry, I realized it was ambiguous as-written, I've clarified. As long as you're comfortable with a higher monthly payment, you'll pay less in total interest by using the $10k as a prepayment in month 1. – bstpierre Mar 31 '11 at 18:16

They should come out just about equal, assuming that you make the same monthly payment in both cases. Using the Calculator @bstpierre mentioned, the monthly payment for a $100k loan at 4% for 20 years is $604. If you had a $90k loan, the payments would be $543. If you pay $604/month on the second loan, putting the extra towards principal, it would work out the same as putting it in the downpayment. The advantage is that you can always pay the $543 if necessary due to unforeseen circumstances. If you have the discipline to make the higher payments, I would put the extra money towards the downpayment. If you think you might be tempted to cut back on the payment sometime in the future, include the extra in the first payment.

  • Good points here. – bstpierre Apr 2 '11 at 14:45

This question carries the risk of comparing apples and oranges. Having said that, one way to make a comparison is described below. First, I would suggest you download the Free Canadian Mortgage Calculator by Vertex42.

In the example, let's say your purchase price was $100000, your current downpayment was $10000, and you take a mortgage at 7% amortized over 25 years. The two options in your question would be decided by either changing the downpayment to $20000 or putting a $10000 additional payment in cell E34.

By making the additional payment, you save a lot of interest only because the monthly payment remains the same. Thus, more of each monthly payment would be applied to your principal balance after your huge additional payment in the first month. Also, your amortization becomes shorter.

On the other hand, increasing your downpayment decreases your total monthly payment given the same 25 year amortization. The interest you pay is higher in this case.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.