How this calculator works
The payment uses the standard amortization formula on your balance, rate and term. The standard federal plan is 10 years.
If you have several loans, enter the total balance and a weighted average rate (each loan’s balance × rate, added up, divided by the total balance).
Extra monthly payments go to principal, which cuts the interest charged in every later month. Ask your servicer to apply extra amounts to principal rather than to future payments.
The comparison table shows the trade-off: longer terms lower the payment but can double the interest you pay.
Worked example
$35,000 at 6.5% over 10 years
- Monthly payment: $397.42.
- Total interest: about $12,690.
- Stretching to 25 years lowers the payment but more than doubles the total interest; check the table.
Questions people ask
Should I pay off student loans early?
If your rate is high and you have emergency savings, paying extra saves interest. If you are pursuing Public Service Loan Forgiveness, extra payments usually don’t help.
What are income-driven repayment plans?
Federal plans that set payments as a share of your discretionary income, with any balance forgiven after 20 to 25 years. Their rules have changed recently; check StudentAid.gov for the plans available now.
Is student loan interest tax deductible?
Up to $2,500 of interest a year can be deducted on your federal return, subject to income limits, without itemizing.
Should I refinance federal loans privately?
It can lower the rate, but you lose federal protections such as income-driven plans, deferment and forgiveness programs.
Last reviewed October 2, 2026