Student Loan Calculator

Federal Student Loan Types

The federal government issues four main loan types through the Direct Loan program. Each serves different borrowers and carries distinct terms.

• Direct Subsidized Loans are for undergraduate students demonstrating financial need. The government pays interest while you are in school at least half-time, during your grace period, and during deferment — making these the most affordable federal loans available.
• Direct Unsubsidized Loans are available to undergraduate and graduate students regardless of financial need. Interest accrues from the date of disbursement. If you choose not to pay interest while in school, it capitalizes — adding to your principal balance.
• Direct PLUS Loans are for graduate students and parents of undergraduates. They require a credit check and carry the highest federal rate. Unlike other federal loans, there is no grace period — repayment begins immediately, though deferment options exist.
• Consolidation Loans combine multiple federal loans into a single payment. The rate is the weighted average of your existing rates, rounded up to the nearest one-eighth percent. Consolidation simplifies repayment but may reset your progress toward forgiveness programs.

Federal Student Loan Interest Rates and Limits

Source: Federal Student Aid (studentaid.gov), U.S. Department of Education

How Interest Capitalization Works

On subsidized loans, the government covers interest while you are enrolled at least half-time and during your grace period — meaning your balance does not grow while you are in school. On unsubsidized loans, interest accrues immediately. If you defer payments, unpaid interest capitalizes — meaning it is added to your principal, and you then pay interest on the higher balance.

Example: You borrow $20,000 in unsubsidized loans at 5.5% during four years of college. Each year, roughly $1,100 in interest accrues. If you defer everything, $4,400 in unpaid interest capitalizes, making your starting balance $24,400 instead of $20,000 — a 22% increase before your first payment is due. Paying interest while in school, even $50-$100/month, prevents this from happening.

Income-Driven Repayment Plans

IDR plans cap your monthly payment at a percentage of your discretionary income (AGI minus 150% of the federal poverty level). After 20-25 years of qualifying payments, the remaining balance is forgiven.

Payment calculation example (SAVE): On a $45,000 salary with $37,000 in student loans: discretionary income = $45,000 - $37,650 (150% of poverty level) = $7,350. Annual payment = $7,350 x 10% = $735. Monthly payment = $61/month — well below the standard $400/month on a 10-year plan. Any remaining balance after 20 years is forgiven.

Public Service Loan Forgiveness (PSLF)

PSLF is the most valuable forgiveness program available. After making 120 qualifying monthly payments (10 years) while working full-time for a qualifying employer — government, 501(c)(3) nonprofit, or other public service organization — your remaining balance is forgiven tax-free.

Requirements: (1) Direct Loans only (consolidate FFEL or Perkins loans first). (2) Must be on an IDR plan. (3) Employers must certify employment annually. (4) Payments must be made while employed full-time by a qualifying employer. PSLF forgiveness is excluded from taxable income under IRC Section 108(f)(1), making it completely tax-free — unlike IDR forgiveness, which is taxable after 2025.

Student Loan Interest Deduction

You can deduct up to $2,500 in student loan interest paid during the year — even if you take the standard deduction. This is an above-the-line deduction that reduces your Adjusted Gross Income (AGI), making it available to all borrowers who qualify.

Income phase-outs (2026): The deduction begins to phase out at $80,000 MAGI for single filers and is fully eliminated at $95,000. For married filing jointly, it phases out between $165,000 and $195,000. This means most borrowers earning under $80,000 receive the full benefit. On a $50,000 salary, the full $2,500 deduction saves roughly $550 in federal taxes at the 22% bracket.

Refinancing: Federal vs Private Loans

Refinancing replaces your existing loans with a new loan, ideally at a lower rate. Private refinancing can drop rates to 4-5% for borrowers with good credit and stable income. However, refinancing federal loans with a private lender permanently removes access to IDR plans, PSLF, deferment, forbearance, and all other federal protections.

When refinancing makes sense: You have a stable high income, no need for federal protections, and can save at least 1-2% on your rate. When to avoid it: You are pursuing PSLF, on an IDR plan, work in public service, or have unstable income. Federal loan protections are the insurance policy — once you refinance privately, they are gone permanently.

Average Student Loan Debt in America

The average student loan balance per borrower in 2026 is approximately $37,000 (source: Federal Reserve Bank of New York). On a standard 10-year repayment plan at 5.5%, that translates to roughly $400/month. Total outstanding student loan debt in the United States exceeds $1.77 trillion, held by approximately 43.5 million borrowers. The median balance — which is more representative than the mean — is approximately $28,950, meaning half of all borrowers owe less than this amount.

Amortization: How Payments Shift Over Time

Student loan amortization works identically to mortgage amortization. In the early years of a 10-year repayment plan, a larger portion of each payment goes toward interest rather than principal. On a $37,000 loan at 5.5%, your first $400 payment allocates roughly $169 to interest and $231 to principal. By the final payment, nearly the entire $400 goes to principal. Over 10 years, you pay approximately $8,000 in total interest on top of the $37,000 borrowed — meaning your total repayment is roughly $45,000.

Internal Resources

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Compound Interest Formula

Assumptions

• Interest compounds monthly (n=12)
• Contributions made at end of each month
• Rate remains constant over entire period
• No taxes or fees deducted

This calculator provides estimates only. Actual investment returns vary and may result in loss of principal.