Student Loan Calculator
Simple Student Loan Calculator
Please provide any three values below to calculate.
Student Loan Repayment Calculator
Use the calculator below to evaluate the student loan payoff options, as well as the interest to be saved. The remaining balance, monthly payment, and interest rate can be found on the monthly student loan bill.
Pay off in 6 years and 2 months
The remaining term of the loan is 9 years and 10 months. By paying an extra $150.00 per month, the loan will be paid off in 6 years and 2 months. It is 3 years and 8 months earlier. This results in savings of $4,421.28 in interest payments.
| Remaining Term | 6 years and 2 months |
| Total Payments | $36,767.26 |
| Total Interest | $6,767.26 |
The Original Payoff Schedule
| Remaining Term | 9 years and 10 months |
| Total Payments | $41,188.54 |
| Total Interest | $11,188.54 |
Student Loan Projection Calculator
Use the calculator below to estimate the loan balance and repayment obligation after graduation. This calculator is mainly for those still in college or who haven't started. Before estimating, it may be helpful to first consult our College Cost Calculator to get a rough idea of how much college may cost.
Result
| Repayment: | $526.96/month |
| Amount Borrowed: | $40,000.00 |
| Balance After Graduation: | $44,263.99 |
| Balance After Grace Period: | $45,790.44 |
| Total Interest: | $23,234.95 |
* For some direct subsidized loans, you do not need to pay interest during school years or the grace period.
* This calculator assumes loans to be repaid each month equally right after graduation or grace period. It also does not take into account any loan fees.
Student Loan Calculator: Exact Monthly Payments and Total Interest Cost
Direct Functionality
A student loan calculator computes fixed monthly payments, total repayment duration, and cumulative interest costs for federal and private education loans. The tool applies the standard amortization formula to loans with fixed annual percentage rates (APR), generating precise payment schedules for borrowers evaluating repayment strategies, refinance opportunities, or income-driven plan comparisons.
Immediate use cases include: determining affordability before borrowing, comparing subsidized versus unsubsidized federal loan costs, calculating savings from extra principal payments, and projecting Public Service Loan Forgiveness (PSLF) timelines.
Core Formula and Mathematical Method
The calculator implements the standard loan amortization equation:
M = P × [r(1+r)ⁿ] / [(1+r)ⁿ − 1]
Where:
- M = Monthly payment
- P = Principal loan balance
- r = Monthly interest rate (APR ÷ 12)
- n = Total number of payments (loan term in years × 12)
Total interest paid equals (M × n) − P. For income-driven repayment (IDR) plans, the calculator modifies this to cap payments at a percentage of discretionary income, with unpaid balances potentially forgiven after 20–25 years—though forgiveness amounts become taxable income under current law unless exempted.
Reference: Federal Student Loan Interest Rates and Terms
| Loan Type | Fixed APR (2023–2024 Academic Year) | Origination Fee | Standard Term | Grace Period |
|---|---|---|---|---|
| Direct Subsidized (Undergraduate) | 5.50% | 1.057% | 10 years | 6 months |
| Direct Unsubsidized (Undergraduate) | 5.50% | 1.057% | 10 years | 6 months |
| Direct Unsubsidized (Graduate/Professional) | 7.05% | 1.057% | 10 years | 6 months |
| Direct PLUS (Graduate/Parent) | 8.05% | 4.228% | 10 years | None (immediate repayment) |
| Perkins Loans (discontinued 2017) | 5.00% | None | 10 years | 9 months |
Source: Federal Student Aid, U.S. Department of Education. Rates set annually by Congress based on 10-year Treasury note yields plus statutory add-ons.
Practical Usage and Operational Nuance
Federal vs. Private Loan Calculation Differences
Federal loans use fixed rates set at disbursement; private loans may offer variable rates tied to SOFR (Secured Overnight Financing Rate) or Prime, typically Prime + 0.50% to Prime + 9.00%. Variable-rate calculators must incorporate rate change scenarios—use the maximum contractual cap (often 18%) for conservative estimates.
Income-Driven Repayment Complexity
IDR plans (SAVE, PAYE, REPAYE, IBR, ICR) require iterative calculations:
- Calculate discretionary income: Adjusted Gross Income − 150% (or 225% for SAVE) of federal poverty guideline for family size
- Apply percentage factor: 5%–20% of discretionary income depending on plan and loan type
- Compare to standard 10-year amortized payment; pay lesser amount
- Project forgiveness timeline and tax liability on forgiven balance
The SAVE plan (effective 2023–2024) reduces undergraduate loan payments to 5% of discretionary income (down from 10%) and eliminates unpaid interest accrual—calculators must model this non-capitalizing interest feature separately.
Capitalization Triggers
Unpaid interest capitalizes (adds to principal) at specific events: end of grace period, end of deferment/forbearance, leaving an IDR plan, or failing to recertify income annually. Calculators should flag these events as principal step-functions, recalculating subsequent payments on the inflated balance.
Worked Example: Standard vs. Extended Repayment
Borrower profile: $35,000 Direct Unsubsidized loan at 5.50% APR
| Repayment Plan | Monthly Payment | Total Payments | Total Interest | Time to Repay |
|---|---|---|---|---|
| Standard (10-year) | $380.02 | $45,602.40 | $10,602.40 | 10 years |
| Extended Fixed (25-year) | $214.94 | $64,482.00 | $29,482.00 | 25 years |
| Extended Graduated (25-year) | $165.00–$496.50 | $68,250.00 | $33,250.00 | 25 years |
| SAVE IDR ($40,000 AGI, single) | $0.00 | $0.00 principal; $17,500 forgiven | $17,500 taxable income | 20 years |
The graduated plan assumes payments increase every 2 years. The SAVE example demonstrates how IDR calculators must integrate tax planning—at 22% marginal rate, the forgiveness tax bomb equals approximately $3,850, though this is waived through 2025 under current policy and may change.
Accuracy Limitations and Data Precision
Calculators operate with these constraints:
- Rate rounding: Federal rates are published to two decimal places; daily interest accrual uses exact values (APR ÷ 365.25), creating ±$0.01–$0.05 monthly payment variance versus simplified 30-day month calculations
- Origination fee deduction: Federal loans disburse net of fees; $10,000 requested yields $9,894.30 actual principal for undergraduate unsubsidized loans. Calculators must distinguish "amount borrowed" from "amount received"
- Prepayment allocation: Extra payments may be applied to future installments rather than principal unless borrower specifies; servicer-specific algorithms vary
- Tax treatment uncertainty: IDR forgiveness taxation status expires 2025; post-2025 projections assume legislative extension or lapse
Verification and Professional Consultation Disclaimer
This calculator generates estimates based on published federal rates and standard amortization mathematics. Actual loan servicer calculations may vary due to payment processing dates, rounding conventions, and servicer-specific policies. For borrowing decisions exceeding $50,000 aggregate principal, consult a certified financial planner or student loan counselor certified by the National Foundation for Credit Counseling (NFCC). For PSLF or IDR enrollment verification, submit Employer Certification Forms annually through the Department of Education's PSLF Help Tool. Tax implications of forgiveness require consultation with a CPA or enrolled agent familiar with IRS Publication 970.