Student Loan Calculator
Compare student loan repayment plans including Standard, Extended, Graduated, and Income-Driven options. See monthly payments and total interest for each plan. See also Loan Calculator and Personal Loan Calculator.
How to Calculate Student Loan Payments
Student loan payments are calculated using the standard amortization formula for fixed-rate loans. The standard repayment plan spreads payments evenly over 10 years (120 months). Extended plans stretch to 25 years for lower monthly payments but more total interest. Graduated plans start with lower payments that increase every two years. Income-driven plans cap payments at a percentage of discretionary income and forgive remaining balances after 20-25 years.
Student Loan Payment Formula
EMI = P × r × (1 + r)^n / ((1 + r)^n − 1)
Where:
P = Loan balance
r = Monthly interest rate (annual rate / 12 / 100)
n = Number of monthly payments
Example
Loan: $35,000 at 5.5% for 10 years
r = 5.5 / 12 / 100 = 0.004583
n = 10 × 12 = 120 months
Monthly Payment = $379.86
Total Paid = $379.86 × 120 = $45,583.20
Total Interest = $45,583.20 − $35,000 = $10,583.20
Student Loan Repayment Comparison
| Loan Amount | Rate | 10-Year Payment | 10-Year Interest | 25-Year Payment | 25-Year Interest |
|---|---|---|---|---|---|
| $20,000 | 5% | $212.13 | $5,455.80 | $116.89 | $15,067.00 |
| $30,000 | 5.5% | $325.61 | $9,073.20 | $184.09 | $25,227.00 |
| $35,000 | 5.5% | $379.86 | $10,583.20 | $214.77 | $29,431.00 |
| $50,000 | 6% | $555.10 | $16,612.00 | $322.15 | $46,645.00 |
| $75,000 | 6.5% | $852.22 | $27,266.40 | $506.69 | $77,007.00 |
| $100,000 | 7% | $1,161.08 | $39,329.60 | $706.78 | $112,034.00 |
Frequently Asked Questions
What are the federal student loan repayment plans?
Federal student loans offer Standard (10-year fixed), Extended (25-year fixed), Graduated (payments increase every 2 years over 10 years), and several Income-Driven plans (SAVE, PAYE, IBR, ICR) that cap payments at 10-20% of discretionary income with forgiveness after 20-25 years.
Should I choose a longer repayment term?
A longer term lowers monthly payments but dramatically increases total interest. A $35,000 loan at 5.5% costs $10,583 in interest over 10 years but $29,431 over 25 years — nearly three times more. Choose the shortest term you can comfortably afford.
Can I refinance student loans?
Yes, private lenders offer refinancing that can lower your interest rate. However, refinancing federal loans into private loans means losing access to federal benefits like income-driven repayment, Public Service Loan Forgiveness, and deferment options.
What is the current federal student loan interest rate?
For the 2024-2025 academic year, federal Direct Subsidized and Unsubsidized loans for undergraduates have a fixed rate of 6.53%. Graduate Direct Unsubsidized loans are 8.08%, and PLUS loans are 9.08%. Rates are set annually by Congress.
Solved Examples
Example 1: Federal student loan repayment (standard plan)
Solution:
Loan balance = $35,000, Interest rate = 5.5%, Term = 10 years (120 months)
Monthly rate = 5.5% / 12 = 0.4583%
EMI = $35,000 × 0.004583 × (1.004583)^120 / [(1.004583)^120 - 1]
EMI = $379.79
Total paid = $379.79 × 120 = $45,575
Total interest = $45,575 - $35,000 = $10,575
Answer: Monthly payment = $379.79, total interest = $10,575 over the standard 10-year plan.
Example 2: Aggressive payoff strategy
Solution:
Same $35,000 at 5.5%, but paying $600/month instead of $380
Payoff time = approximately 68 months (5 years 8 months)
Total interest = $5,681
Interest saved vs standard plan = $10,575 - $5,681 = $4,894
Time saved = 52 months (4 years 4 months)
Answer: Paying $600/month saves $4,894 in interest and eliminates the loan 4+ years early.
Example 3: Refinancing student loans
Solution:
Current: $50,000 at 6.8%, 10-year term → EMI = $575, Total interest = $19,044
Refinanced: $50,000 at 4.5%, 7-year term → EMI = $691, Total interest = $8,016
Monthly increase = $116 more per month
Interest savings = $19,044 - $8,016 = $11,028
Answer: Refinancing at a lower rate and shorter term saves $11,028 in interest.
Practice Questions
Try these on your own:
- $28,000 student loan at 4.99% for 10 years. Monthly payment? (Answer: $296.93)
- You owe $45,000 at 6.5% on the standard plan. Total interest over 10 years? (Answer: ≈$15,754)
- If you can deduct up to $2,500 in student loan interest and you're in the 22% bracket, what's your tax savings? (Answer: $550)
- $60,000 total student debt across 4 loans. Average rate 5.8%. Standard plan payment? (Answer: ≈$660/month)
- Income-driven repayment caps at 10% of discretionary income. Income = $50,000, poverty line = $15,060. Monthly payment? (Answer: ≈$291)
Common Mistakes to Avoid
A critical mistake is choosing an income-driven repayment plan without understanding that lower payments mean more interest accrues, potentially increasing your total balance (negative amortization). Another error is refinancing federal loans into private loans — you permanently lose access to income-driven plans, Public Service Loan Forgiveness (PSLF), and federal forbearance protections. Many borrowers don't realize that interest accrues during school on unsubsidized loans, so a $20,000 loan can become $24,000+ by graduation. Failing to claim the student loan interest deduction (up to $2,500/year) leaves money on the table. Also, paying minimum across all loans equally instead of targeting the highest-rate loan first (avalanche method) costs more in total interest. Finally, many graduates defer payments during grace periods without realizing interest still accumulates.
Key Takeaways
- Federal student loan rates are fixed; current rates range from 5.5-8.05% depending on loan type.
- The standard repayment plan is 10 years — shorter terms save significantly on interest.
- Income-driven plans cap payments at 10-20% of discretionary income but extend the payoff timeline.
- Student loan interest is tax-deductible up to $2,500/year if income is below the phase-out threshold.
- Use the avalanche method (highest rate first) to minimize total interest, or snowball (smallest balance first) for psychological wins.
- Only refinance federal loans to private if you don't need IDR plans or PSLF — you lose all federal protections.