Enter your balance, interest rate, and term to see your monthly payment, total interest paid, and total amount repaid.
Standard student loan payments use the same fixed amortization formula as any other installment loan: payment = balance × i ÷ (1 − (1 + i)−n), where i is the monthly interest rate (annual rate ÷ 12 ÷ 100) and n is the number of monthly payments. Each payment splits between interest on the remaining balance and principal, with the interest share shrinking and the principal share growing over the life of the loan.
No — the underlying amortization math is identical for both federal and private student loans once you know the balance, rate, and term. What differs is the protections available: federal loans offer options like income-driven repayment, deferment, and certain loan forgiveness programs that private loans typically don't provide. See the Student Loan Repayment Calculator to explore those federal-specific repayment options.
Extra payments go straight to principal, which cuts the total interest you'll pay and shortens the loan term, since interest only accrues on the remaining balance. Use the Debt Payoff Calculator to see exactly how extra monthly payments change your payoff timeline and total cost.
Rates vary by loan type, whether the loan is federal or private, and the specific year it was disbursed, so there isn't one universal number worth assuming here. Check studentaid.gov for current federal loan rates, or your private lender's actual offer, and plug that real number in above for an accurate result.
Worked example: a $30,000 loan at 5.5% over a 10-year term has a monthly payment of $325.58. Over 120 payments, total interest comes to $9,069.46, bringing the total amount repaid to $39,069.46.
Weighing income-driven repayment instead? See the Student Loan Repayment Calculator.