Student Loan Repayment Calculator (US) — Compare Federal Plans
Compare the three main federal student loan repayment approaches side by side: Standard 10-year (fixed payments, lowest total cost), Extended 25-year (lower monthly payment, much higher total cost), and Income-Driven Repayment — IDR (payment capped at 10% of discretionary income, with forgiveness after 20 years).
%
Fixed payment under the default federal Standard Repayment Plan
- 1
Monthly interest rate
r = 6.53% ÷ 1200 = 0.005442 - 2
Number of payments
n = 10 × 12 = 120 - 3
Growth factor (1+r)ⁿ
1.005442ⁿ = 1.9179 - 4
Standard 10-year monthly payment
30,000 × 0.005442 × 1.9179 ÷ (1.9179 − 1) = 341.10
How does this calculator work?
Standard 10yr: lowest total cost; Extended 25yr: lower monthly but ~3× more interest; IDR: 10% of AGI above 1.5 × FPL monthly, with 20-year forgiveness. A $30,000 loan at 6.53% costs about $338/month standard, $200/month extended, or an income-based amount on IDR. 2024 FPL figures used; edit income and family size for your situation.
Formula
How this is calculated
The federal Standard Repayment Plan splits the loan into 120 equal monthly payments over 10 years using the standard amortisation formula. It has the highest monthly payment but the lowest lifetime interest cost. Extended Repayment stretches to 300 payments (25 years), reducing each payment by roughly 40% but nearly tripling total interest on a typical $30,000 loan.
Income-Driven Repayment (IDR) caps monthly payments at a percentage of discretionary income — typically 10% of the amount by which your Adjusted Gross Income (AGI) exceeds 150% of the federal poverty level (FPL) for your family size. The FPL figures used here are the 2024 guidelines for the 48 contiguous states ($15,060 for 1 person, +$5,380 per additional member). If your payment is less than monthly interest, the balance may grow over time; any remaining balance after 20 years (undergrad loans) can be forgiven.
This calculator fixes income and family size for simplicity. In practice, IDR requires annual recertification of income and family size, and payments change each year. The SAVE plan was blocked by federal courts in 2025; check studentaid.gov for the latest available plans and their specific payment percentages and poverty-line multipliers.
Frequently asked questions
The Standard 10-year plan pays the least total interest if you can afford the higher monthly payment. IDR can save more when your balance is very high relative to income and you qualify for forgiveness — but if you end up paying off the loan before 20 years, IDR total costs are similar to or more than Extended. Run the numbers for your specific balance and income.
Yes. Federal borrowers can change their repayment plan at any time by contacting their loan servicer. Switching to IDR is free and can be done online at studentaid.gov. Switching from IDR back to Standard or Extended resets some conditions but does not erase qualifying payments already made for PSLF.
Graduated repayment starts with lower payments that increase every two years, on the assumption that income grows over time. The total repayment is slightly higher than the Standard plan. This calculator does not model graduated repayment because the payment schedule requires knowing the specific step-up structure provided by your servicer.
TG we-Calculate Editorial Team. (2026). Student Loan Repayment Calculator (US) — Compare Federal Plans [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/student-loan-repayment-us-calculator
TG we-Calculate Editorial Team. "Student Loan Repayment Calculator (US) — Compare Federal Plans." TG we-Calculate. 2026. https://we-calculate.com/calculator/student-loan-repayment-us-calculator.
TG we-Calculate Editorial Team, "Student Loan Repayment Calculator (US) — Compare Federal Plans," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/student-loan-repayment-us-calculator
@misc{wecalculate_student_loan_repayment_us_calculator, title = {Student Loan Repayment Calculator (US) — Compare Federal Plans}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/student-loan-repayment-us-calculator}}, year = {2026}, note = {TG we-Calculate} }
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