Student Loan Payment Calculator

Federal vs. private student loans

Federal student loans are issued by the U.S. Department of Education. Their interest rates are set by Congress each year and are fixed for the life of the loan once disbursed. Rates are published at StudentAid.gov and apply to loans disbursed from July 1 of each year through June 30 of the next. Federal loans offer significant borrower protections not available on private loans, including income-driven repayment plans, Public Service Loan Forgiveness, deferment and forbearance options, and discharge in certain circumstances such as total and permanent disability.

Private student loans are issued by banks, credit unions, and other private lenders. Interest rates are set by the lender and depend on your credit history, income, and other factors. Private loans may be fixed or variable rate. To find your rate, check your loan documents or log into your lender's servicer portal. Private loans generally do not offer income-driven repayment, PSLF, or the same deferment and forbearance protections as federal loans.

This calculator applies equally to both loan types. The key difference is where you find your rate: federal borrowers should log into StudentAid.gov; private borrowers should check their loan documents or servicer portal.

Standard repayment vs. income-driven repayment

Standard repayment divides your balance and interest into equal monthly payments over a fixed term (10 years for Standard, up to 25 years for Extended). This calculator covers standard fixed-payment amortization. You will pay the least total interest on a shorter term, but your monthly payment will be higher.

Income-driven repayment (IDR) plans set your monthly payment as a percentage of your discretionary income rather than a fixed amortization amount. Eligible plans include Income-Based Repayment (IBR), Pay As You Earn (PAYE), Income-Contingent Repayment (ICR), and the SAVE plan. IDR formulas are set by federal regulations and have been subject to legal and regulatory change. This calculator does not estimate IDR payments. Use the official Loan Simulator at StudentAid.gov for IDR comparisons, as it reflects current plan availability and eligibility rules.

For most borrowers with a stable income, Standard repayment minimises total interest paid. IDR plans can lower monthly payments but typically result in more interest paid over time, though any remaining balance after 20 or 25 years of qualifying payments may be forgiven (with potential tax implications). PSLF forgives remaining balances after 10 years for qualifying public service employees.

Worked example

Default values: $35,000 loan balance, 6.54% annual interest rate, Standard 10-year term (120 months):

1. Monthly rate r = 6.54 / 100 / 12 = 0.00545
2. n = 120 months
3. Monthly payment = 35,000 x 0.00545 x (1.00545)^120 / ((1.00545)^120 - 1)
4. Monthly payment = approximately $394.79
5. Total paid = 394.79 x 120 = approximately $47,374.80
6. Total interest = $47,374.80 - $35,000 = approximately $12,374.80

The 6.54% rate is a default for illustration only. Federal loan rates change each July 1. Your actual rate appears in your loan disclosure or at StudentAid.gov.