Student Loan Calculator
See what your student loans will really cost: the monthly payment, the total interest over the life of the loan, and how much time and money even a small extra payment can save you.
How much is a $30,000 student loan per month?
Student loan: A student loan is money borrowed to pay for education, repaid with interest — most simply on a standard 10-year plan of equal monthly payments. Borrowing $30,000 at 5.5% APR on the standard 10-year plan costs $325.58 a month and $39,069 in total, which is $9,069 of interest. Adding just $100 a month extra ends the loan about 34 months early and saves roughly $2,750 of interest.
How to calculate a student loan payment
- Take the amount borrowed, the APR and the repayment term in months.
- Convert the APR to a monthly rate by dividing it by 12.
- Apply the amortization formula to get the fixed monthly payment.
- To model extra payments, add them to the monthly payment and count the months until the balance reaches zero — the difference is the interest saved.
Source: Federal Student Aid — Types of Loans · Federal Student Aid — Repayment Plans
Payoff schedule by year
With no extra payment this follows the standard amortization of your chosen term.
How this student loan calculator works
Student loans amortize just like other installment loans: each monthly payment covers that month's interest first, and the remainder chips away at the principal. This calculator takes your total balance, your interest rate and a repayment term, computes the fixed monthly payment with the standard amortization formula, and then simulates the loan month by month to build the payoff table. If you add an extra monthly payment, the simulation applies it entirely to principal — which is how extra payments attack interest, because a lower balance next month means less interest accrues.
The standard federal repayment plan is 10 years, and the defaults above reflect a very typical case: $30,000 borrowed at 5.5%. Stretch the term to 20 or 25 years (as extended and some income-driven plans effectively do) and watch what happens to total interest — it is the most expensive "convenience" in student borrowing.
The repayment formula
P = loan balance · r = APR ÷ 12 · n = months in the term
Worked example
On the standard plan, $30,000 at 5.5% APR over 10 years gives a monthly payment of $325.58. Over 120 payments you repay $39,069 in total, so the degree's financing charge is $9,069 of interest — nearly a third of the amount borrowed, on top of it. Now add just $100 a month extra: the loan dies about 34 months early and you save roughly $2,750 of interest. Enter the defaults above and try it — the "interest saved" line shows the exact figures.
Choosing a repayment strategy
- Standard 10-year plan. Highest payment, lowest total interest, and the benchmark every other plan should be compared against.
- Extended terms (20–25 years). Payments drop a lot — on the example loan, to about $184 a month at 25 years — but total interest grows to roughly $25,300. Use extended terms as a bridge, not a destination.
- Income-driven repayment. Payments are capped as a share of income, with forgiveness after 20–25 years of payments on federal loans. It protects cash flow, but slow amortization means balances can grow even while you pay. This calculator models fixed-payment plans; check your servicer's figures for IDR specifics.
- Extra payments and the avalanche method. If you hold several loans, put every spare dollar against the highest-rate loan while paying minimums on the rest. Specify to your servicer, in writing, that extra money goes to principal on that specific loan — otherwise it may be spread around or applied to future payments.
- Refinancing. Private refinancing can cut the rate for borrowers with strong credit and stable income, but it permanently gives up federal protections — income-driven plans, deferment and forgiveness programs. Run the new rate here first and compare total interest, not just the payment.
While you are still in school
Interest on unsubsidized loans accrues from the day the money is disbursed. Paying just the interest while studying — about $138 a month on $30,000 at 5.5% — stops the balance from capitalizing and quietly saves thousands over the repayment years. When graduation comes, compare your first real payment against the other debts competing for your paycheck, starting with anything charging credit-card rates; our credit card payoff calculator shows why those come first, and the compound interest calculator shows what the same dollars do once they are invested instead.
Frequently asked questions
How much interest will I pay on $30,000 of student loans?
At 5.5% APR on the standard 10-year plan, about $9,070 — bringing the total repaid to roughly $39,070. Stretch the same loan to 25 years and interest balloons to about $25,300, nearly as much as the original loan. Your exact figure depends on your rate, so enter it above for your real number.
Is it better to pay extra on student loans or invest?
Mathematically, paying down a loan earns a guaranteed return equal to its interest rate, with zero risk. If your loan rate is 5.5% and long-run market returns average higher but fluctuate, the comparison is close; most people benefit from a split: capture any employer retirement match first (an instant 50–100% return), pay off high-rate debt, then invest. Emotionally, many borrowers simply prefer being debt-free — that has value too.
What happens if I only make minimum payments on an income-driven plan?
Your payment is capped by income, but if it does not cover the monthly interest, the unpaid interest can capitalize and your balance grows despite paying every month. Forgiveness after 20–25 years can still make IDR the right choice for high balances relative to income, but run your numbers and re-check them whenever your income changes.
Can I pay off my student loans early with no penalty?
Yes. Federal student loans and virtually all private student loans have no prepayment penalty. You can pay extra monthly, make lump-sum payments after a bonus or tax refund, or pay the loan off entirely at any time. Just instruct your servicer to apply overpayments to principal on your highest-rate loan.
What is the average student loan payment?
The typical federal borrower owes around $28,000–$38,000, which on the standard plan at recent rates works out to roughly $300–$400 a month. Averages hide the spread, though — your payment is determined by your own balance, rate and term, which is exactly what this calculator shows.
Sources
- Federal Student Aid — Types of Loans — Federal loan types, interest rates and fees, from the U.S. Department of Education.
- Federal Student Aid — Repayment Plans — The standard 10-year repayment plan this calculator models.