How to use this student loan calculator
- Loan balance: what you owe now. If you have several federal loans, you can add them together and use a weighted average rate, or run each loan separately.
- Interest rate: the fixed rate on your loan.
- Repayment term: 10, 20 or 25 years.
- Extra payment: any amount you'd like to pay each month on top of the required payment.
You'll see the standard monthly payment and total interest, the same figures with your extra payment, and how many months and how much interest the extra saves.
How the payment is calculated
With an extra payment, the calculator adds it to every payment and works month by month: interest is charged on the remaining balance, and everything above the interest reduces the principal. A lower balance means less interest next month, so extra payments compound in your favor.
Worked example
Doubling the extra to $200 a month saves $5,099.50 and finishes 53 months early.
Longer terms cost more
Longer terms lower the monthly payment but greatly increase total interest. Here's the same $30,000 at 6.5%:
| Term | Monthly payment | Total interest | Saved by paying $100 extra |
|---|---|---|---|
| 10 years | $340.64 | $10,877.41 | $3,347.04 |
| 20 years | $223.67 | $23,681.74 | $11,904.18 |
| 25 years | $202.56 | $30,769.58 | $17,631.15 |
On a 25-year term, an extra $100 a month cuts the repayment from 300 months to 143 months. The longer the term, the more an extra payment saves.
Federal repayment plans in brief
For federal Direct Loans, the Standard Repayment Plan uses fixed payments over up to 10 years. Borrowers with larger balances may qualify for an Extended plan of up to 25 years, which is why this calculator offers 10, 20 and 25-year terms. Income-driven repayment plans base the payment on income instead of a fixed schedule, and their rules have changed in recent years, so check the current options on StudentAid.gov or with your loan servicer.
Tips for paying off student loans faster
- Target the highest rate first. If you have several loans, direct extra payments to the one with the highest interest rate.
- Give your servicer instructions. Ask for extra payments to go to principal, not to prepay future months.
- Use automatic payments. Federal loan servicers offer a small interest rate reduction for enrolling in auto-pay; check the current discount with your servicer.
- Put raises to work. When your income rises, increase the extra payment before your spending grows to match.
- Compare refinancing carefully. Refinancing federal loans into a private loan can lower your rate, but you lose federal benefits such as income-driven plans and forgiveness programs.
If you have several loans
Many borrowers have more than one student loan, often at different rates. To use this calculator for all of them at once, add up the balances and use a weighted average rate: multiply each balance by its rate, add the results and divide by the total balance. For example, $10,000 at 5% and $20,000 at 7% gives (10,000 × 5 + 20,000 × 7) ÷ 30,000 ≈ 6.33%.
For extra payments, though, it's usually better to target one loan at a time. Paying extra on the highest-rate loan first saves the most interest, the same idea as the debt avalanche. Ask your servicer to apply extra payments to that specific loan.
Paying extra or investing?
Every extra dollar on a loan earns a guaranteed return equal to the loan's interest rate. Whether that beats investing depends on your rate, your other goals and how comfortable you are with risk. Many people first make sure they get any employer retirement match and have an emergency fund, then split extra money between paying down loans and saving.
Keeping track of your loans
Federal student loan details, including balances, rates and your servicer, are listed in your StudentAid.gov account. Private loans appear on your credit report and your lender's statements. Keeping a simple list of each loan's balance and rate makes it easier to decide where extra payments should go.
What this calculator doesn't include
The calculator assumes a fixed rate, fixed monthly payments and interest calculated monthly. Federal student loans accrue simple interest daily, so actual figures can differ by small amounts. It doesn't model income-driven plans, deferment, forbearance, capitalized interest or forgiveness. Use your servicer's statements and StudentAid.gov for the exact details of your loans.