https://mortgage-master.replit.app/
This is the most practical app I generated with Replit. I was always frustrated with the quality of other mortgage calculators I found online. My bank has a terrible one, so I decided to build my own version. The main thing I was looking after is to see how early a mortgage can be paid off if additional monthly payments are made and how making additional lump sum payments can change that. And the most important feature, how much would be saved in interest payments.
My process involved asking Replit Agent to create a web-based mortgage calculator application with the following core features:
- Input fields for loan details (Principal Balance, Fixed Interest Rate, Original Loan Amount, Original Loan Date, Maturity Date)
- Calculate and display Monthly Payment
- Generate Amortization Schedule and show standard Loan Payoff date
- Allow input of additional monthly payments and lump sum payments
- Calculate and display new Loan Payoff date based on extra payments
- Show interest savings from early payoff
Once I had the initial prototype, I used Replit Assistant to make further tweaks, play around with having some default values for all inputs, improve the amortization schedule view, minor UI tweaks, etc.
I am very happy with how this turned out and it’s the only mortgage calculator app I will use moving forward. 