Student Loan Calculator

Understanding Federal vs. Private Student Loans

This student loan calculator estimates your monthly payment, total interest paid, payoff date, and full amortization schedule. Student loans fall into two categories: federal loans (issued by the US Department of Education) and private loans (issued by banks and credit unions). Federal loans offer significant advantages — including income-driven repayment plans capped at 5–10% of discretionary income, Public Service Loan Forgiveness (PSLF), deferment and forbearance options, and fixed interest rates set annually by Congress.

For 2025–2026, federal undergraduate Direct Loan rates are 6.53% for subsidized and unsubsidized loans; graduate unsubsidized loans are 8.08%; Parent and Grad PLUS loans are 9.08%. Private loan rates range from 4% (excellent credit with cosigner) to 16%+ (fair credit). The average undergraduate borrower leaves school with approximately $29,000–$32,000 in federal student loan debt. Always exhaust federal loan eligibility before borrowing private — the flexibility of federal loans is worth the rate premium in most scenarios.

How Student Loan Payments Are Calculated

For standard and extended fixed repayment, the monthly payment is calculated using the standard amortization formula:

M = P × r(1+r)^n / ((1+r)^n − 1)

Where P is the loan principal, r is the monthly interest rate (annual rate ÷ 12), and n is the number of monthly payments. This formula ensures that each payment covers the current month's interest plus a portion of the principal, so the loan is exactly paid off at the end of the term.

Every payment you make is split between interest and principal. Early in the loan, most of your payment goes to interest. As the balance falls, more goes to principal — this is called amortization. The amortization table in the calculator above shows this breakdown for your first 12 months.

Comparing Repayment Plans

Federal student loans come with multiple repayment options, each with different monthly payments and total costs:

• Standard (10-year) — highest monthly payment, lowest total interest. This is the default plan and the fastest payoff for most borrowers.
• Extended (25-year) — lower monthly payment but you pay roughly twice the interest. Best if cash flow is tight and you don't qualify for IDR.
• Graduated — starts at ~50% of the standard payment and increases ~7% every 2 years. Designed for borrowers whose income will grow significantly over time.
• Income-Driven (IDR) — payment is 10% of your discretionary income. Remaining balance is forgiven after 20–25 years. Best for low-income borrowers or those pursuing Public Service Loan Forgiveness (PSLF).

Federal vs. Private Student Loans

Federal loans offer protections and flexibility that private loans do not. Federal borrowers can switch repayment plans, enroll in income-driven programs, apply for deferment or forbearance, and potentially qualify for forgiveness. Private loans are issued by banks and credit unions — rates depend on your credit score, and repayment options are limited to whatever the lender offers.

The 2024–2025 federal undergraduate Direct Loan rate is 6.54%. Private loan rates can range from 4% (excellent credit, cosigner) to 15% or higher (fair credit, no cosigner). Always exhaust federal loan options before turning to private loans. Use our tuition calculator to estimate how much you might need to borrow in the first place.

Income-Driven Repayment: How It Works

IDR plans calculate your payment based on your discretionary income — the amount you earn above 150% of the federal poverty guideline for your family size. For a single borrower with a $30,000 income and a poverty line of $15,060, discretionary income is approximately $7,410 ($30,000 − $22,590). The monthly payment would be 10% of $7,410 ÷ 12 = $61.75/month.

If your income is below 150% of the poverty line, your required monthly payment is $0 — though interest continues to accrue on unsubsidized loans. After 20 years (SAVE, PAYE, IBR for new borrowers) or 25 years (ICR, older IBR), remaining balances are forgiven. Forgiven amounts are currently treated as taxable income under federal law, though this is subject to change.

Public Service Loan Forgiveness (PSLF)

If you work full-time for a qualifying government or nonprofit employer, you may qualify for PSLF after making 120 qualifying monthly payments (10 years) under an IDR plan. The remaining balance is forgiven tax-free. PSLF works only with Direct Loans; FFEL loans must be consolidated first. Use the Federal Student Aid PSLF Tool to track qualifying employment and payment count.

Strategies to Pay Off Student Loans Faster

• Make extra principal payments — even an extra $50/month can shave years off a 10-year loan and save thousands in interest
• Pay biweekly instead of monthly — 26 half-payments equal 13 full payments per year, reducing your term by about a year
• Refinance at a lower rate — if your credit has improved since graduation, private refinancing may offer a lower rate. Warning: refinancing federal loans into a private loan forfeits all federal protections
• Apply bonuses and tax refunds to principal — lump-sum principal payments have a compounding benefit since they reduce all future interest charges
• Track your academic costs — use the tuition calculator to plan future semesters and minimize total borrowing