Student Loan Payoff Calculator
Calculate the monthly payment for a student loan given its balance, interest rate, and repayment term, using standard loan amortization math.
The amortisation formula it solves
You fix the term and it returns the payment that retires the balance exactly on schedule. With r the monthly rate and n the number of payments:
r = annual rate / 100 / 12, n = years x 12
payment = B x r x (1 + r)^n / ((1 + r)^n - 1)
total interest = payment x n - B$30,000 at 6% over ten years gives $333.06 a month, $39,967.38 handed over in total and $9,967.38 of it interest. A zero rate is handled separately as balance over months, and fractional terms are allowed.
What stretching the term does
| Term | Monthly | Total interest |
|---|---|---|
| 5 years | $579.98 | $4,799 |
| 10 years | $333.06 | $9,967 |
| 15 years | $253.16 | $15,568 |
| 25 years | $193.29 | $27,987 |
Going from ten years to twenty-five saves $140 a month and costs $18,020. The payment stops falling much after fifteen years while the interest keeps climbing: past that point you buy a smaller bill with almost pure interest.
Frequently asked questions
What is the monthly payment on $30,000 of student loans?
At 6% over ten years, $333.06. Over five years it is $579.98 and over twenty $214.93 - the term moves the payment far more than the rate does.
How much of the first payment is interest?
$150 of that $333.06, because a $30,000 balance at 6% accrues 0.5% in its first month. The other $183.06 clears principal, and that share grows every month as the balance shrinks.
Why is my servicer's payment different from this?
Usually because the account holds several loans at different rates, each amortised separately and then added up, or because the term you were placed on is not the one entered here.