Modelling home finances

I’ve just uploaded a rough-and-ready program for modelling mortgage offsetting.  Mortgage offset accounts are like savings accounts linked to a mortgage, but instead of earning interest they reduce the interest charged by offsetting the loan amount.

There are mortgage lenders that let you manage offset accounts on-line, and even show nice graphs to show the predicted effect of offsetting (i.e. how much less time it will take to pay off the mortgage) but this graph is a lot more configurable than any I’ve seen.

You can use it to say that you’ve a certain amount in the offset account, but you’ll be withdrawing an amount each month; or you expect a fixed term deposit to mature in 6 months; or there’s a big purchase on the horizon that will reduce the size of the offset.

The project is called expendable, and I’m hosting it at  Click on the picture above to take a closer look.

3 Responses to “Modelling home finances”

  1. Ricky Zhou says:

    Just a heads up: Your project link goes to the right place, but the text says instead of


  2. tim says:

    Thanks. Fixed.

  3. […] is a quick guide to using Expendable for modelling home finances.  If you want to be able to predict how much time or interest can be […]