Loan Interest Calculator
Loans & DebtSee exactly how much total interest you’ll pay over the life of a loan.
Changing the display currency only changes the symbol shown — amounts aren't converted, since this tool doesn't use live exchange rates.
Total interest you'll pay
$0
Monthly payment: $0
Total paid: $0
That's of the loan amount paid in interest alone.
How this is calculated
Uses the standard fixed-rate amortization formula M = P·r(1+r)^n / ((1+r)^n − 1), where P is the loan amount, r is the monthly interest rate, and n is the number of monthly payments. Each payment is split into interest (balance × monthly rate) and principal (the rest), and the balance declines every month until it reaches zero at the final payment. Total interest is the sum of the interest portion of every payment across the full term.
Frequently asked questions
- Why is total interest so much higher on longer terms?
- A longer term spreads payments out, so the balance declines more slowly and accrues interest for longer — even at the same rate, doubling the term roughly doubles or more the total interest paid.
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