Student Loan Calculator

Understanding Student Loan Repayment

Federal student loans offer several repayment plan options, each with a different monthly payment and a different total cost. The right choice depends on your income today, your expected career trajectory, and how much you value low payments now versus paying less overall. This calculator estimates your monthly payment, payoff timeline, and total interest for the Standard, Extended, and Graduated plans, and charts the three balance curves so you can compare them at a glance.

Under the fixed plans, each payment is calculated with the standard amortization formula M = P[r(1+r)^n] / [(1+r)^n − 1], where P is your balance, r is the monthly interest rate (annual rate ÷ 12), and n is the number of monthly payments. Every payment covers the interest accrued that month, and the rest reduces your principal. Because interest is charged on the outstanding balance, the longer a balance stays unpaid, the more total interest accrues.

A Worked Example

Suppose you owe $35,000 at a hypothetical 5.5% annual rate. On a Standard 10-year plan the monthly payment is roughly $380, and you would pay around $10,600 in interest over the full term. Stretching the same balance to a longer term would drop the monthly payment but raise total interest substantially, because the balance is outstanding for many more years. Enter your own balance, rate, and plan above to see how the numbers shift.

Standard Repayment

The default plan uses fixed monthly payments over a relatively short term. It costs the least in total interest and clears your debt fastest, but it carries the highest monthly payment of the three options here. Choose it when your budget can comfortably handle the payment, since it minimizes lifetime cost.

Extended Repayment

Extended repayment stretches your payments over a much longer term, significantly lowering your monthly obligation. It suits borrowers who need immediate cash-flow relief. The trade-off is paying substantially more total interest, because the balance remains outstanding far longer than under the Standard plan.

Graduated Repayment

Graduated repayment starts with lower payments that step up periodically, typically every couple of years. It is designed for borrowers who expect their income to rise steadily over time. Total cost usually falls between the Standard and Extended plans, and the rising payments require you to be confident your earnings will keep pace.

How Interest Accrues and Capitalizes

Understanding when interest accrues helps you avoid surprises. On many loans, interest begins building from the day the loan is disbursed, even while you are still in school or in a grace period. If that interest is not paid as it accrues, it can be capitalized, meaning it is added to your principal balance. From that point on, you pay interest on a larger balance, so the loan grows faster than the rate alone would suggest. Where your budget allows, making interest-only payments during school, deferment, or forbearance keeps the principal from ballooning and lowers your lifetime cost.

How to Choose and Common Mistakes

When comparing plans, look at both the monthly payment and the total interest, not just the payment. A frequent mistake is selecting the lowest payment by default; that can quietly add years and a large amount of interest to your loan. If a fixed payment is unaffordable, an income-driven plan (not modeled here) may be a better fit than simply extending the term, and it can offer eventual forgiveness for some borrowers. Always confirm specifics with your loan servicer.

A few practical habits can save money no matter which plan you pick:

• Target the highest-rate loan first: If you hold several loans, directing extra payments to the one with the highest rate reduces total interest fastest.
• Specify where extra payments go: Ask your servicer to apply additional amounts to principal so they shorten the loan rather than prepaying future bills.
• Re-evaluate after income changes: A raise may let you switch to a faster plan, while a setback may justify temporary relief.
• Protect federal benefits: Think carefully before refinancing federal loans privately, since you would forfeit income-driven options and forgiveness programs.

When to Use a Different Calculator

This calculator focuses on comparing student loan repayment plans. If you want a payment-by-payment breakdown or want to test extra principal payments on a single fixed-rate balance, use the amortization calculator. For a simple payment estimate on any general fixed-rate loan, the loan calculator is the quicker tool.