🎓 Student Loan Calculator
Estimate your monthly student loan payment, total interest, and see how much extra payments could save you.
Loan Details
Your Loan Summary
Standard payment uses the fixed amortization formula over your chosen term. Adding extra monthly payments reduces the principal faster, shortening your payoff time and lowering total interest paid.
How the Student Loan Calculator Works
This calculator uses the standard loan amortization formula to compute your fixed monthly payment, then simulates the payoff with any extra payments applied directly to principal each month.
Formula
Number of Payments (n) = Term (years) × 12
Monthly Payment = L × r × (1 + r)ⁿ / [(1 + r)ⁿ − 1]
(If r = 0: Monthly Payment = L / n)
Worked Example
For a $30,000 loan at 5.5% over a 10-year term: the monthly rate is 5.5% / 12 = 0.4583%, giving a standard monthly payment of $325.58 and total interest of $9,069.46 over 120 months. Adding a $50 extra monthly payment ($375.58 total) pays off the loan in 100 months instead of 120 — a savings of 20 months and $1,627.99 in interest, for a reduced total interest of $7,441.47.
Frequently Asked Questions
How does extra payment affect my student loan?
Extra payments applied directly to principal reduce the balance faster, which means less interest accrues each month — shortening your payoff time and lowering total interest paid.
What's a typical student loan interest rate?
Federal student loan rates vary by year and loan type, often ranging from about 5% to 8%, while private loans can range more widely based on credit.
Should I pay off student loans early?
Paying extra can save significant interest, especially on higher-rate loans. Compare the loan's rate to what you could earn investing, and check whether your loan has prepayment penalties (federal loans do not).