Mortgage

Mortgage is a simple calculator intended to aid comprehension of the true cost of a mortgage.

Installation

To install mortgage, simply:

pip install mortgage

Documentation

Documentation is available at https://mortgage.readthedocs.io

How To Use

This package is intended to help understand the true cost of a mortgage. It also can help you easily compare between different mortgages.

Begin by importing the loan class

from mortgage import Loan

Create a simple mortgage

from mortgage import Loan

loan = Loan(principal=200000, interest=.06, term=30)

View a summary of pertinent mortgage information by calling the summarize property.

from mortgage import Loan

loan = Loan(principal=200000, interest=.06, term=30)
loan.summarize

>>> Original Balance:         $    200,000
>>> Interest Rate:                    0.06 %
>>> APY:                              6.17 %
>>> APR:                              6.00 %
>>> Term:                               30 years
>>> Monthly Payment:          $    1199.10

>>> Total principal payments: $ 200,000.00
>>> Total interest payments:  $ 231,676.38
>>> Total payments:           $ 431,676.38
>>> Interest to principal:           115.8 %
>>> Years to pay:                     30.0

Particularly telling is the Interest to Principal ratio. With the mortgage terms above, you will pay 115% of the original balance in interest! Compare that to the same loan with a 15 year term below

from mortgage import Loan

loan = Loan(principal=200000, interest=.06, term=15)
loan.summarize

>>> Original Balance:         $    200,000
>>> Interest Rate:                    0.06 %
>>> APY:                              6.17 %
>>> APR:                              6.00 %
>>> Term:                               15 years
>>> Monthly Payment:          $    1687.71

>>> Total principal payments: $ 200,000.00
>>> Total interest payments:  $ 103,788.46
>>> Total payments:           $ 303,788.46
>>> Interest to principal:            51.9 %
>>> Years to pay:                     15.0

In this case, you only pay 52% of the original loan balance in interest. Obviously, the shorter the term with all else equal, the less interest you'll pay. But it helps to know exactly how much more/less you'll pay.

Run The Test Cases

From the top level directory, run the following command:

pytest

Thank You

Thanks for checking out the package! I hope you find it useful.

Feel free to open an issue with suggestions, imporovements, ideas, etc.