java-installment-loan-calculator

A java installment loan calculator library that calculates the monthly installment amounts for a loan.

Features

• Loan Calculation: The program allows users to enter the loan amount, interest rate, and loan duration in months.
• Monthly Installment Calculation: It calculates the fixed monthly installment amount.
• Amortization Schedule: It generates an amortization schedule that shows the breakdown of each payment, including the principal amount, interest amount, and remaining balance.
• Due date calculation: The program calculates the due date for each installment, trying to keep the same day of the month whenever possible.
  Eg: if you set a due date on the 31st of May, it will automatically recalculate the dates as follow:
  • 31st of May
  • 30th of June (sice Jun has 30 days, the program will automatically decrese the due date to the 30th of the month).
  • 31st of July
  • and so on.
• Advance payment: possibility to define an advance payment amount, which will be excluded from the interest calculation (See Example 2)

Getting Started

Prerequisites

To run the Installment Plan Calculator program, you need to have the following:

• Java Development Kit (JDK) 1.8 installed on your machine.
• A Java IDE or text editor for editing and running the Java code. This is a Netbeans-Ant project.
• Apache Ant™ if you prefer not using ad IDE

Bulding the Project

1. Clone or download the project repository to your local machine.

$ git clone https://github.com/lfriends/java-installment-loan-calculator.git
$ cd java-installment-loan-calculator

2. if you use Apache Ant™:

$ cd ./java-installment-loan-calculator
$ ant

.OR.

3. Open the project in your preferred IDE or text editor (Eg Netbeans, Eclipse -> Menu -> File -> Open projects from file system ... )
4. then run the "Build" or "Run" command

Runing the Project

You can import the Jar in your project, or generate a new Loan Plan simulation directrly from a command-line interface:

$ java -jar "lfIntallmentPlan.jar"

Example 1: Usage

$ java -jar "lfIntallmentPlan.jar"

====== Installment Calculator  ::  github.com/lfriends ======
Please enter the loan amount (Eg 10000):
10000
Please enter the advance payment amount (Eg 1000 or 0):
0
Please enter the interest rate in % (Eg 4.5):
4.5
Please enter the loan duration in monts (Eg 12):
12
Please enter the 1st due date (DD/MM/YY .or. DDMMYY) (Eg 31/12/23 .or 311223):
311223
-----------------------------------------------------------------------------
Principal ............... 10.000,00
Interest rate ........... 4,50%
Duration ................ 12 months
Monthly payments ........ 853,79
Intarest paid ........... 245,48
Total paid .............. 10.245,48

Month | Due date  | Installme | Principal | Interest  | Balance   | Debt Paid 
-----------------------------------------------------------------------------
1     | 17/05/23  | 853,79    | 816,29    | 37,50     | 9.183,71  | 816,29    
2     | 17/06/23  | 853,79    | 819,35    | 34,44     | 8.364,36  | 1.635,64  
3     | 17/07/23  | 853,79    | 822,42    | 31,37     | 7.541,94  | 2.458,06  
...   | ...       | ...       | ...       | ...       | ...       | ...       
12    | 30/11/24  | 853,79    | 850,60    | 3,19      | 0,00      | 10.000,00 
-----------------------------------------------------------------------------
Total             | 10.245,42 | 10.000,00 | 245,42    |                      
-----------------------------------------------------------------------------

Example 2: with Advance Payment

Advance payment amount will be excluded from interest calculation

====== Installment Calculator  ::  github.com/lfriends ======
Please enter the loan amount (Eg 10000):
11000
Please enter the **advance payment amount** (Eg 1000 or 0):
1000
Please enter the interest rate in % (Eg 4.5):
4.5
Please enter the loan duration in monts (Eg 12):
12
Please enter the first due date or press ENTER for current date (Format: DD/MM/YY .or. DDMMYY - Eg 31/12/23 or 311223):

-----------------------------------------------------------------------------
Principal ............... 11.000,00
Advance payment ......... 1.000,00
Interest rate ........... 4,50%
Duration ................ 12 months
Monthly payments ........ 853,79
Intarest paid ........... 245,48
Total paid .............. 11.245,48

Month | Due date  | Installme | Principal | Interest  | Balance   | Debt Paid 
-----------------------------------------------------------------------------
ADV P | --        | 1.000,00  | 1.000,00  | 0,00      | 10.245,48 | 1.000,00
1     | 04/07/23  | 853,79    | 816,29    | 37,50     | 9.183,71  | 1.816,29  
2     | 04/08/23  | 853,79    | 819,35    | 34,44     | 8.364,36  | 2.635,64  
3     | 04/09/23  | 853,79    | 822,42    | 31,37     | 7.541,94  | 3.458,06  
...   | ...       | ...       | ...       | ...       | ...       | ...    
12    | 04/06/24  | 853,79    | 850,55    | 3,24      | 0,00      | 11.000,00 
-----------------------------------------------------------------------------
Total             | 11.245,48 | 11.000,00 | 245,48    |                      
-----------------------------------------------------------------------------

License

This project is licensed under the MIT License. Feel free to use, modify, and distribute the code for personal or commercial purposes.