Student Loan Monthly Payment Calculator
Estimate your monthly student loan payment using the standard amortization formula. Enter your loan details below to see your required monthly payment, total amount paid, and total interest paid over the life of the loan.
Formula
The standard loan amortization formula is used to calculate the fixed monthly payment:
M = P × [r(1 + r)n] / [(1 + r)n − 1]
- M = Monthly payment
- P = Principal loan amount
- r = Monthly interest rate = Annual rate / 12
- n = Total number of monthly payments = Years × 12
If the annual interest rate is 0%, the formula simplifies to: M = P / n
Total Amount Paid = M × n
Total Interest Paid = Total Amount Paid − P
When an extra monthly payment is added, the payoff timeline is simulated month-by-month, reducing the principal faster and shortening the loan term.
Assumptions & References
- Payments are made monthly and on time with no grace periods or deferments.
- The interest rate is fixed for the entire repayment term (does not apply to variable-rate loans).
- No origination fees, prepayment penalties, or capitalized interest are included in this calculation.
- Extra payments are applied entirely to the principal balance, which is standard practice for most federal and private student loans.
- Federal student loan interest rates for 2024–2025: Undergraduate Direct Loans at 6.53%, Graduate Direct Loans at 8.08%, and Direct PLUS Loans at 9.08% (source: Federal Student Aid).
- The standard federal repayment plan term is 10 years; income-driven repayment plans may extend up to 20–25 years.
- This calculator is for estimation purposes only. Contact your loan servicer for exact payment amounts.