Student Loan Repayment Calculator
This student loan repayment calculator uses the standard amortizing loan payment formula to calculate your fixed monthly payment, total amount repaid over the life of the loan, and total interest paid. It applies to both federal and private student loans with fixed interest rates. Enter your current loan balance, the annual interest rate, and the repayment term in years. The standard federal repayment term is 10 years, but you can enter any term. The formula is the same one used by federal loan servicers: monthly payment equals principal multiplied by the monthly rate, multiplied by one plus the monthly rate raised to the power of total payments, all divided by one plus the monthly rate raised to the total payments minus one. Results show your monthly payment, total paid across all payments, and total interest as a dollar amount and as a percentage of the original loan. Adjusting the term shows the trade-off between lower monthly payments (longer term) and less total interest (shorter term).
Monthly payment: --
Monthly payment formula
M = P x (r(1+r)^n) / ((1+r)^n - 1)
where r = annual rate / 12, n = years x 12
Worked example
Loan: $30,000 at 6.50% for 10 years.
- Monthly rate r = 6.50% / 12 = 0.5417%
- n = 10 x 12 = 120 payments
- M = 30,000 x (0.005417 x 1.005417^120) / (1.005417^120 - 1)
- Monthly payment = $340.44
- Total paid = 340.44 x 120 = $40,852.80
- Total interest = 40,852.80 - 30,000 = $10,852.80
Frequently asked questions
What is the standard federal student loan repayment term?
The Standard Repayment Plan for federal Direct Loans is 10 years (120 monthly payments). This plan typically results in the lowest total interest paid compared to extended or income-driven repayment plans. The monthly payment under Standard Repayment is fixed for the life of the loan. Federal loan servicers automatically enroll borrowers in this plan unless an alternative is chosen.
What are current federal student loan interest rates?
Federal student loan interest rates are set annually by Congress based on the 10-year Treasury note rate plus a fixed add-on. Rates change each academic year for new loans disbursed on or after July 1. For the most current rates, see the official Federal Student Aid website at studentaid.gov/understand-aid/types/loans/interest-rates. This calculator accepts any rate you enter and does not hardcode a specific rate.
How is my monthly student loan payment calculated?
The standard amortizing payment formula is: M = P * (r*(1+r)^n) / ((1+r)^n - 1), where P is the principal, r is the monthly interest rate (annual rate divided by 12), and n is the total number of monthly payments. This formula ensures your loan is paid off completely at the end of the term with equal monthly payments.
What happens if I pay extra each month?
Extra payments reduce your principal faster, which reduces the amount of interest you accrue over the life of the loan. If you apply extra payments to principal, you can pay off the loan before the term ends and pay significantly less total interest. Contact your loan servicer to ensure extra payments are applied to principal, not credited toward future payments.
What is the difference between subsidized and unsubsidized loans?
Subsidized Direct Loans do not accrue interest while you are enrolled at least half-time, during the six-month grace period after leaving school, or during deferment periods. Unsubsidized Direct Loans begin accruing interest from disbursement. If unsubsidized interest is not paid during school, it capitalizes (adds to principal) at repayment, increasing the total amount owed.
Sources
- Federal Student Aid, Repayment Plans: studentaid.gov/manage-loans/repayment/plans.
- Federal Student Aid, Interest Rates: studentaid.gov/understand-aid/types/loans/interest-rates.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. General information only; contact your loan servicer for personalized advice.