[GNC] Working with compound interest on varying amounts

[Hal Vaughan]

For the past few years, for my business that is mostly about renovating or restoring houses and reselling them (not flipping - this work takes time), I’ve used a Python library I wrote myself to handle accounting.  It was basically made up mostly of stuff I had, with a few new things added in.

I would like to switch over to GnuCash.  Luckily, since I’m at a slow point and between projects, I can do that without worrying about converting old data for older LLCs and projects.

There’s one issue I’m not sure can be handled by GnuCash, so I’d like to find out about it before trying to switch over.

I use a line of credit.  Luckily the interest rate is basically constant.  (There’s a slight flux, but not much.)  The problem is its compounded and, of course, every time I withdraw money from the credit line or pay any back, the principal amount changes.  I’m hoping, at this point, people are saying, "Oh, yeah, just do this…."

But just in case there’s a need for clarification, if I withdraw $50,000 to purchase a house on January 1, then, on the 15th, withdraw $10,000 for roofing work, need to figure out the total owed to that credit line on 1/31, and the interest rate is 3%, then I have to figure compound interest on $50,000 at 3% from 1/1 to 1/15.  Then I have to add $10,000 to that amount to calculate the interest on the $50,000 plus 15 days of interest, plus $10,000, plus the interest from the 15th to the 30th, at 3%, to get a clear number for what I owe.

Can I have this done automatically on an account?  If not, how can I easily keep track of this in GnuCash?


Thank you!


Hal