Erik Halvorson

Engineer, Software Developer, Amateur Photographer

Simple Interest Calculator for Android

A few years ago, my wife's car died (cracked engine block -- hope this never happens to you). In the market for a new car for the first time in our lives, we applied for financing at the dealership. Our financier pulled a fast one on us -- selling us a higher interest rate than we really wanted, in exchange for a lower payment and longer repayment time. Of course, I was familiar with compound interest, but having never come face-to-face with it, how was I expected to know what that extra APR really meant? A few days later I wrote a compound interest calculator that answers that question, but you can't use that in a dealership or bank. So I thought, why not port to Android?

This handy app computes compound interest for a simple interest loan or deposit account. It supports monthly compounding and can solve for any of the basic parameters for such a loan (current value, APR, number of payments, payment amount, and future value) given the other four values. You can use this, for example, to examine the cost of paying twice your monthly payment, or see what would happen to your loan if the APR were higher. In my case, it would've let me see that my extra percentage point would cost us almost $1000 over the length of our loan. Use it to check your financing, work out repayment options, or all of the above. Computed values can be stored to history. The program also contains a short manual (with examples) that describes how to use it.

Download version 1.0.0 (requires Android phone)
Application in Android Marketplace (requires Android phone)
Screenshots: (click for higher resolution)