Kreditrechner Shiny App

Overview

The "Kreditrechner" is a Shiny application designed to help users calculate various aspects of a home loan. It allows users to input their financial details and visualize the loan amortization schedule, calculate the monthly payment, loan duration, and remaining balance after the fixed interest period.

Features

• Input financial parameters such as house price, down payment (Eigenkapital), additional costs as a percentage, repayment rate, interest rate, and fixed interest duration.
• Calculate the loan amount, monthly payment, total loan duration, and remaining balance after the fixed interest period.
• Visualize the remaining debt over time and the breakdown of monthly payments into interest and principal components using interactive plots.

Requirements

To run this app, you’ll need the following R libraries installed:

• shiny
• shinydashboard
• tidyverse
• lubridate

Usage Instructions

1. Launch the App: Deploy and run this app using R, RStudio, or another environment supporting Shiny applications.

2. Input Parameters:

   • Eigenkapital: Enter your available funds for the down payment.
   • Hauspreis: Specify the total house price.
   • Nebenkosten (% vom Hauspreis): Input additional costs as a percentage of the house price.
   • Tilgungsrate in %: Set the repayment rate percentage.
   • Zinsbindungsdauer: Choose the duration for the fixed interest rate (5, 10, or 15 years).
   • Zinssatz eff. p.a. (%): Enter the effective annual interest rate.

3. View Calculations: The app displays:

   • Kreditbetrag: The total loan amount.
   • Monatl. Rate: The monthly installment amount.
   • Laufzeit: Total loan term in years and months.
   • Restschuld nach Zinsbindung: Remaining debt after the fixed interest period.

4. Visualizations:

   • Remaining Debt Plot: Tracks the remaining loan balance over time.
   • Rate Components Plot: Illustrates the monthly payment components into interest and principal repayment.

How It Works

• Backend Calculations: The server function computes the amortization schedule based on user inputs. It determines the loan amount, monthly payment, loan duration, and remaining balance after the fixed interest period.
• Visualization: The app uses ggplot2 to plot the amortization schedule and payment components, providing users with a clear understanding of their loan repayment process.

Customize

Feel free to modify the app’s layout or functionalities by editing the ui and server sections of the script as per your specific requirements or preferences.

Credits

Developed using Shiny and R’s tidyverse packages, leveraging data visualization and reactive programming capabilities to model loan computations effectively.