README for Business::US_Amort
                                        Time-stamp: "2000-05-14 01:14:45 MDT"

     Business::US_Amort - class encapsulating US-style amortization

       use Business::US_Amort;
       my $loan = Business::US_Amort->new;

       my $add_before_50_amt = 700;
       sub add_before_50 {
         my $this = $_[0];
         if($this->{'_month_count'} == 50) {
           $this->{'_monthly_payment'} += $add_before_50_amt;


       print "Total paid toward interest: ", $loan->total_paid_interest, "\n";

     This class encapsulates amortization calculations figured
     according to what I've been led to believe is the usual
     algorithm for loans in the USA.

     I used to think amortization was simple, just the output of
     an algorithm that'd take just principle, term, and interest
     rate, and return the monthly payment and maybe something
     like total paid toward interest.  However, I discovered that
     there's a need for loan calculations where, say, between the
     49th and 50th month, your interest rate drops, or where you
     decide to add $100 to your monthly payment in the 32nd

     So I wrote this class, so that I could amortize simply in
     simple cases while still allowing any kind of strangeness in
     complex cases.

     This program is distributed in the hope that it will be
     useful, but without any warranty; without even the implied
     warranty of merchantability or fitness for a particular

     But let me know if it gives you any problems, OK?

     Copyright 1999, 2000, Sean M. Burke, all
     rights reserved.  This program is free software; you can
     redistribute it and/or modify it under the same terms as
     Perl itself.

     Sean M. Burke


This suite requires Perl 5; I've only used it under Perl 5.004, so for
anything lower, you're on your own.

Business::US_Amort doesn't use any nonstandard modules.


You install Business::US_Amort, as you would install any perl module
library, by running these commands:

   perl Makefile.PL
   make test
   make install

If you want to install a private copy of Business::US_Amort in your home
directory, then you should try to produce the initial Makefile with
something like this command:

  perl Makefile.PL LIB=~/perl


POD-format documentation is included in Business::US_Amort.  POD is
readable with the 'perldoc' utility.  See ChangeLog for recent


Don't bother with the makefiles.  Just make a Business folder under
your MacPerl site_lib or lib directory and move into


Questions, bug reports, useful code bits, and suggestions for
Business::US_Amort should just be sent to me at


The latest version of Business::US_Amort is available from the
Comprehensive Perl Archive Network (CPAN).  Visit
<> to find a CPAN site near you.