I am searching for a simple explanation/formula for computation
of finance charges. I am programing an invoicing application for a
jeweler. A typical invoice might be for one ring at $1500.

After a 30 day grace period, how do I go about computing the maximum
legal finance charge (and how does one discover that maximum?).
Is it just a certain percentage per day. And I guess you have to
make certain that the yearly annual percentage is below the legal maximum.

I am looking at the back of a credit card bill to get some tips.

The bottom of the bill posts a daily rate of .05918% and an annual percentage of 26.60. The back of the credit card statement mentions
something called "the Periodic Rate".

I used a search engine for "finance charge computation/formula"...
and didnt really find a simple formula or explanation.

The credit card statment speaks of computing an "average daily balance" with is a level of complication beyond what I need. I simply need to compute finance charges on one invoice that is more than 30 days old.

I suppose I could compute one years finance charge at 18%, and then figure what it would be per day.

Thanks for any tips/suggestions, explanations.

I dont really need dBase code, just a simple formula/explanation
of how to compute.

Thanks!

Bill Buell