Enter your balance, rate and payment to see the month your student loans will be paid off, and how much interest an extra payment or a lump sum saves you.
Student loan payoff calculator
Your extra payments save you $3,118.03 in interest and get you out 2 years, 9 months sooner. Without them, you'd pay for 9 years, 8 months and $10,439.33 in interest.
Without the extra, your required payment wouldn't even cover the interest. The extra is what gets this loan paid off.
Add an amount under Extra each month or a one-time payment to see how much interest you'd save.
Estimates only. Your servicer or lender sets your actual payment.
How to use it
Pick whether you know your monthly payment or your loan term. Most people know the payment, it’s on your bill.
Use your total balance and your average rate if you have more than one loan. For a sharper answer, run your highest-rate loan on its own, since that’s where extra money does the most.
Extra each month is what you’d add on top of the bill. The one-time payment is money you’d put toward the balance today, like a tax refund or a bonus.
How the payoff math works
Every month, interest is your balance times your rate, divided by 12. Your payment covers that interest first and the rest cuts the balance.
Extra money skips the interest and goes straight to principal. So next month’s interest is a little smaller, more of your regular payment hits principal, and the month after that it’s smaller again. That snowball is why $100 a month can take years off a loan.
If you enter a term instead of a payment, we work out the payment with the standard loan formula: the balance times the monthly rate, divided by one minus (1 plus the monthly rate) raised to the power of minus the number of months. It’s the same formula behind a 10-year Standard plan.
If your payment doesn’t even cover a month’s interest, the calculator tells you. That balance would never go down.
Before you send extra to a federal loan
Federal student loans have no prepayment penalty, so extra is always allowed. But tell your servicer to apply it to principal and not to push your next due date forward.
On RAP, an extra payment automatically advances your due date unless you opt out, and a month with no payment due gets no $50 principal match. If you’re headed for PSLF, extra payments just shrink the amount that would be forgiven.
Three examples
Example: $30,000 at 6.5%, $350 a month, plus $100
- Without the extra
- 9 years, 8 months
- With $100 extra
- 6 years, 11 months
- Interest saved
- $3,118.03
- Total interest
- $7,321.30
How we got it: at $350 a month the loan costs $10,439.33 in interest. Adding $100 a month cuts that to $7,321.30 and finishes 2 years and 9 months sooner.
Example: $35,000 at 6.5% on a 10-year plan, plus $50
- Required payment
- $397.42/mo
- Paid off in
- 8 years, 7 months
- Interest saved
- $2,039.75
- Total interest
- $10,650.40
How we got it: the 10-year payment on $35,000 at 6.5% is $397.42, with $12,690.15 of interest. An extra $50 a month saves $2,039.75 and ends the loan 1 year and 5 months early.
Example: $20,000 at 6.52%, a $2,000 tax refund
- Required payment
- $227.30/mo
- Paid off in
- 8 years, 8 months
- Interest saved
- $1,676.37
- Time saved
- 1 year, 4 months
How we got it: 6.52% is the undergraduate Direct Loan rate for loans first disbursed July 1, 2026 to June 30, 2027. On a 10-year plan the payment is $227.30. Putting a $2,000 refund on the balance today, with no other change, saves $1,676.37.
The pattern holds every time. Money sent sooner saves more, and even small amounts add up when the rate is high.
Where to go next
Our guide to paying off student loans fast covers where to find the extra money and which loan to hit first. A few bucks a month from a side hustle or a tighter budget with one of the best budgeting apps goes a long way here.
Got a high rate on private loans? Check whether a lower rate beats extra payments with our student loan refinance calculator. Struggling to make the payment at all? Our RAP calculator shows what an income-driven payment would be.
Next stepFor your exact federal loan numbers, use the official Repayment Calculator on StudentAid.gov, or see all our student loan tools.
Payoff calculator FAQ
It depends on your balance, rate and payment. On a 10-year Standard plan it takes 10 years. For example, $30,000 at 6.5% with a $350 payment takes 9 years and 8 months, and adding $100 a month cuts that to 6 years and 11 months. Put your own numbers in the calculator above to see your date.
Not on federal student loans. They have no prepayment penalty. For a private loan, check your loan agreement before you send extra.
Tell your servicer, in writing or in your online account, to apply extra money to principal and not to advance your next due date. Otherwise it can be treated as an early payment of next month’s bill.
You can, but know the catch. On RAP an extra payment advances your due date unless you opt out, and months with no payment due get no $50 principal match. If you’re going for PSLF, paying extra only shrinks the amount that would be forgiven.
Dollar for dollar, money sent sooner saves more. A $2,000 payment today on $20,000 at 6.52% saves $1,676.37 in interest. Spreading the same $2,000 over the next 12 months saves $1,554.95. Both are worth doing.
Estimates only. Your servicer or lender sets your actual payment. Interest is figured monthly with a fixed rate (servicers charge it daily), extra money goes to principal, and the payoff date counts from next month.
Sources (4)
We use primary sources: Federal Student Aid and the Electronic Code of Federal Regulations.
- Federal Student Aid. Federal versus private loans. studentaid.gov. Accessed October 22, 2026.
- Federal Student Aid. Interest rates and fees for federal student loans. studentaid.gov. Accessed October 22, 2026.
- Electronic Code of Federal Regulations. 34 CFR 685.209, Income-driven repayment plans. ecfr.gov. Accessed October 22, 2026.
- Federal Student Aid. Repayment Calculator. studentaid.gov. Accessed October 22, 2026.