Student Loan Calculator: Estimate Your Monthly Payments & Total Cost
Our free student loan calculator helps you estimate your monthly payment, total interest costs, and full repayment timeline for any federal or private student loan. Simply enter your loan balance, interest rate, and repayment term to see an instant breakdown of what you'll owe. You can also model how making extra monthly payments could save you thousands in interest and help you become debt-free sooner.
Enter the total amount you borrowed or plan to borrow.
Federal undergraduate loans are typically 5–7%. Private loans vary by lender and credit score.
Standard federal repayment is 10 years. Extended plans can go up to 25 years.
Standard uses fixed monthly payments. Interest-only payments cover only accrued interest and do not reduce principal.
Optional additional amount paid each month beyond the required payment to pay off the loan faster.
Your results will appear here
How to Use This Calculator
1. Enter your total loan amount in the 'Total Loan Amount' field — this is the principal balance you borrowed or plan to borrow. 2. Input your annual interest rate as a percentage; check your loan servicer's portal or promissory note for the exact rate. 3. Choose your repayment term from the dropdown — federal standard plans default to 10 years, but you can select up to 25 years. 4. Select your repayment plan type: 'Standard (Fixed)' for equal monthly payments that pay down principal and interest, or 'Interest Only' to see what payments would be if you only covered accruing interest. 5. Optionally, enter any extra amount you plan to pay each month beyond the minimum to see how it reduces your interest and shortens your loan term. 6. Review your results instantly — your monthly payment, total amount paid, total interest, actual payoff time, and interest saved are all displayed.
How Student Loan Payments Are Calculated
Student loan monthly payments are determined using the standard amortization formula, which spreads your principal and interest evenly across all payments so that your loan is fully paid off by the end of your term.
The Monthly Payment Formula
The formula for a fixed monthly payment is:
- 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)
How Interest Accrues
Each month, your lender calculates interest on your remaining balance. In the early months of repayment, a larger portion of your payment goes toward interest. As the principal shrinks over time, more of each payment reduces the principal — this is called amortization.
Federal vs. Private Student Loans
Federal student loans (Direct Subsidized, Direct Unsubsidized, PLUS) have fixed interest rates set annually by Congress. Private loans may carry fixed or variable rates determined by the lender based on your credit score and financial history. Private loans generally lack the income-driven repayment and forgiveness options available for federal loans.
Repayment Plan Types
- Standard Repayment: Fixed monthly payments over 10 years — the default for federal loans and usually the lowest total interest cost.
- Extended Repayment: Lower monthly payments spread over up to 25 years, resulting in higher total interest.
- Income-Driven Repayment (IDR): Payments based on your income and family size; remaining balances may be forgiven after 20–25 years.
- Graduated Repayment: Payments start low and increase every two years.
The Power of Extra Payments
Making even small additional payments each month can dramatically reduce your total interest costs and shorten your loan term. For example, paying an extra $100/month on a $30,000 loan at 5.5% over 10 years could save over $1,500 in interest and pay off the loan more than a year early. Every dollar of extra payment goes directly to reducing your principal balance.
Capitalized Interest
If your loan was in deferment or forbearance, any unpaid interest may have been capitalized — added to your principal balance. This increases the amount on which future interest is calculated, raising your effective cost. Always check your current balance with your loan servicer for the most accurate calculation.