Payoff v0.2.1

Fixed-rate loan calculations made easy.


This library is in pre-alpha state, and is provided as-is, with no warranty or support of any kind. I am not a financial professional, and this library is not suggested for any production environments.


  • Ease of use: A simple, dependency-free way to do basic loan payback calculations. It should help easily compare early payback situations on an existing loan, or different terms prospective loans for the same amount.
  • ES6 + Babel: This is my first attempt at using Ecmascript 6 (and Babel for legacy transpiling). Would like to make sure it’s making good use of the new features, while maintaining ES5 compatibility.
  • Docker compilation: should be able to develop on any machine, using a containerized compiler defined in the repository.


The easiest way to compile this library's source code into the minified result is via Docker container. It will install the node application and all dependencies inside a virtual container. If you have Docker and Docker Compose installed, then a single command line...

# in root /payoff/ directory
docker-compose up

...will run a full build on the /src source files, placing the result into /dist, and running the unit tests.


  • Asynchronous constructor option
  • Create contribution guidelines
  • More unit test coverage