This loan calculator tool performs interest calculations for fixed rate loans.
The implementation is no different to your standard compound interest formula, but implemented in Simulink!
This submission may therefore interest (no pun intended) beginners looking at how to implement a basic problem in Simulink.
The submission may interest people looking to start a new loan, or optimize their existing loan with additional repayments.
Extension to variable rate loans would be trivial (homework) if for example you wanted to perform a sensitivity study for future interest rate changes.