qfinbox.tvm.loans.total_interest_paid

qfinbox.tvm.loans.total_interest_paid(principal: float, annual_rate: float, years: float, payments_per_year: int = 12) → float[source]

Calculate total interest paid over the life of the loan.

Parameters:

  • principal (float) – Loan principal amount.

  • annual_rate (float) – Annual interest rate (as decimal).

  • years (float) – Loan term in years.

  • payments_per_year (int, default 12) – Number of payments per year.

Returns:

Total interest paid.

Return type:

float

Examples

>>> total_interest_paid(300000, 0.05, 30)
279767.35