Student Loan Calculator — Monthly Payment & Total Interest
Find out exactly what your student loan costs each month and in total. Enter your balance, annual interest rate, and repayment term to get the fixed monthly payment, total interest paid, and a declining-balance chart over the life of the loan.
%
years
Fixed monthly payment to fully repay the loan
- 1
Monthly interest rate
r = 6.53% ÷ 1200 = 0.005442 - 2
Number of payments
n = 10 × 12 = 120 - 3
Growth factor
(1 + r)ⁿ = 1.005442ⁿ = 1.9179How much one unit of balance grows over the entire repayment term. - 4
Monthly payment
30,000 × 0.005442 × 1.9179 ÷ (1.9179 − 1) = 341.10
How does this calculator work?
Monthly payment = P·r·(1+r)^n / ((1+r)^n − 1). A $30,000 loan at 6.53% (2024–25 federal undergrad rate) over 10 years costs about $338/month and roughly $40,600 total — around $10,600 in interest. Longer terms lower monthly payments but sharply increase total interest. Enter your own balance, rate, and term to see exact figures.
Formula
How this is calculated
Student loans are repaid on a standard amortising schedule: each equal monthly payment covers the interest accrued on the remaining balance and the remainder chips away at principal. The formula M = P·r·(1+r)^n / ((1+r)^n − 1) gives the fixed monthly payment that retires the debt exactly in n months, where P is the principal and r the monthly interest rate (annual rate ÷ 12 ÷ 100). In early payments most of the money goes to interest; by the final payments it is almost all principal.
For US federal loans, the standard repayment term is 10 years (120 payments). The 2024–25 interest rates set by Congress are 6.53% for undergraduate Direct Subsidised and Unsubsidised loans, 8.08% for graduate Unsubsidised, and 9.08% for PLUS loans — edit the rate field to match your actual loan. Private student loan rates vary by lender and credit history and are often higher than federal rates.
This calculator assumes a fixed interest rate and equal payments throughout. It does not model income-driven repayment (IDR) plans, deferment, forbearance, or loan forgiveness programmes. Use the Student Loan Repayment (US) calculator to compare standard vs income-driven plans, and the Student Loan Forgiveness calculator to estimate PSLF or IDR forgiveness amounts.
Frequently asked questions
The default plan is 10 years (120 monthly payments). Extended repayment stretches to 25 years, significantly reducing the monthly payment but multiplying total interest. Income-driven plans (IDR) cap payments at 5–15% of discretionary income and forgive any remaining balance after 20–25 years.
On a $30,000 loan over 10 years, moving from 5% to 7% APR increases the monthly payment by about $30 and adds roughly $3,600 in total interest. Even a 0.25% autopay interest rate discount (offered by most federal and private servicers) saves hundreds over the life of the loan.
Extending the term reduces the monthly burden but dramatically increases total interest. A $30,000 loan at 6.53% costs about $8,600 in interest over 10 years and about $24,000 over 25 years. If cash flow is the issue, an income-driven plan that adjusts to your actual income is usually a better option than a fixed extended term.
TG we-Calculate Editorial Team. (2026). Student Loan Calculator — Monthly Payment & Total Interest [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/student-loan-calculator
TG we-Calculate Editorial Team. "Student Loan Calculator — Monthly Payment & Total Interest." TG we-Calculate. 2026. https://we-calculate.com/calculator/student-loan-calculator.
TG we-Calculate Editorial Team, "Student Loan Calculator — Monthly Payment & Total Interest," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/student-loan-calculator
@misc{wecalculate_student_loan_calculator, title = {Student Loan Calculator — Monthly Payment & Total Interest}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/student-loan-calculator}}, year = {2026}, note = {TG we-Calculate} }
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