Loan interest paid calculator
Useful to see how much interest you paid in a given year, or how much goes to interest at any stage of the loan.
Loading the tool…
Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter loan amount, annual interest rate, loan term, from payment # and to payment #.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Balance after k payments = P × (1 + r)^k − payment × ((1 + r)^k − 1) ÷ r. Principal from payment a to b = balance(a − 1) − balance(b), interest = payment × (b − a + 1) − principal.
Example
Inputs: Loan amount = 100,000, Annual interest rate = 6 %, Loan term = 30 years, From payment # = 1, To payment # = 12. Result: Interest paid in range: 5,966.59; Principal paid in range: 1,228.01; Total interest on the loan: 115,838.19.
Limits and caveats
- Assumes equal payments with no extra payments or rate changes.
- Whether any interest is tax deductible depends on your local rules.
Questions about this tool
How do I get the interest for year three?
Choose payment 25 to payment 36, since each year has 12 payments.
Why does interest fall each year?
The balance drops with every payment, so interest is charged on a smaller amount.
Does it match the amortization schedule?
Yes, it equals the interest and principal columns of the schedule added up for the same payments.