Student Loan Calculator — Estimate Your Monthly Payment & Payoff Timeline
Calculate student loan payments, total interest, and payoff date for any repayment plan
How to use Student Loan Calculator
Free student loan calculator. Enter loan balance, interest rate, and repayment term to see your monthly payment, total interest, total repayment cost, and exact payoff date. Works for federal and private student loans.
A student loan calculator shows your monthly payment, total interest paid, and payoff date based on your current loan balance, interest rate, and repayment term. Use it to compare the standard 10-year federal repayment plan against shorter or longer terms, evaluate the cost of income-driven repayment plans, or see how much extra monthly payments would shorten your payoff timeline. Both federal and private student loans use the same amortisation formula, so this calculator works for any fixed-rate student loan.
How to use this Student Loan Calculator
- 1Enter your current loan balance — the total amount you owe today, including capitalised interest if applicable.
- 2Enter the annual interest rate on your loan. Find this on your servicer's website or on StudentAid.gov for federal loans.
- 3Enter the repayment term in years. Federal standard repayment is 10 years. Extended repayment: 25 years. Income-driven plans: 20–25 years.
- 4Read your monthly payment, total interest paid, and total repayment amount.
- 5Try a shorter term to see how much interest you save — or add an extra monthly payment amount to see how much faster you can pay off the loan.
Student loan payment formula explained
Student loans use the same standard amortisation formula as mortgages and personal loans. Interest accrues daily on federal loans (daily interest = balance × annual rate ÷ 365), but payments are typically monthly. The formula below gives your fixed monthly payment for a standard repayment plan.
| Variable | Meaning |
|---|---|
| M | Monthly payment |
| P | Principal (current loan balance) |
| r | Monthly interest rate (annual rate ÷ 12) |
| n | Total payments (years × 12) |
Student loan example: $40,000 at 6.5% on a 10-year standard plan
- 01Loan balance: $40,000. Annual rate: 6.5% → monthly rate r = 0.065 ÷ 12 = 0.005417.
- 02Repayment term: 10 years → n = 10 × 12 = 120 payments.
- 03Monthly payment = $40,000 × [0.005417 × (1.005417)^120] / [(1.005417)^120 − 1]
- 04(1.005417)^120 = 1.9063. Monthly payment = $40,000 × [0.005417 × 1.9063] / [0.9063]
- 05Monthly payment = $40,000 × 0.010329 / 0.9063 = $45.26… = $454.17
Result
Monthly payment: $454.17. Total paid over 10 years: $54,500.40. Total interest: $14,500.40.
What affects your student loan payment and payoff cost?
Repayment plan type
Federal student loans offer multiple repayment plans: Standard (10 years, fixed payment), Graduated (10 years, payments start low and increase), Extended (25 years, lower payment, far more interest), and Income-Driven plans (IBR, PAYE, SAVE — payments 5–10% of discretionary income, forgiveness at 20–25 years). Private loans typically offer standard or extended fixed terms only.
Interest rate — federal vs private
Federal Direct Loan rates are set by Congress each year and are fixed for the life of the loan. 2025–2026 rates: undergraduate subsidised/unsubsidised 6.53%, graduate unsubsidised 8.08%, Parent/Grad PLUS 9.08%. Private loan rates depend on your credit score and can be fixed or variable — ranging from 4% to 16%+ depending on creditworthiness.
Interest capitalisation
During deferment, forbearance, or income-driven plans where your payment doesn't cover accruing interest, unpaid interest is capitalised (added to the principal). This increases the balance you're paying interest on and can significantly increase your total repayment cost. Paying at least the accruing interest monthly prevents capitalisation.
Public Service Loan Forgiveness (PSLF)
Federal borrowers who work for government or qualifying non-profit organisations and make 120 qualifying payments on an income-driven plan can have the remaining balance forgiven tax-free. If you qualify, an income-driven plan with low payments may cost less total than aggressive early repayment.
Extra payments
Every extra payment on a student loan goes directly to principal, accelerating payoff. Adding $100/month to a $40,000 loan at 6.5% (standard 10-year plan) saves $4,200 in interest and pays off the loan 2 years early. Direct your servicer to apply extra payments to principal, not future payments.
Refinancing
Refinancing federal loans into a private loan can lower your interest rate if your credit score has improved since graduation — but permanently eliminates access to federal benefits: income-driven repayment, PSLF, deferment, and forbearance. Refinancing is worth considering only if you are not pursuing PSLF, have a stable income, and can get a rate at least 1% lower.
Tips and things to know
- ✓Log in to StudentAid.gov to see all your federal loan balances, interest rates, and servicer information in one place before running any calculations.
- ✓If you are on an income-driven repayment plan, simulate the standard 10-year plan in this calculator first — it gives a useful benchmark for how much the IDR plan is costing you in additional interest.
- ✓Making payments during your grace period (the 6 months after graduation before payments are required) goes entirely to principal — no interest has capitalised yet — making it the highest-leverage time to pay down your balance.
- ✓If you have multiple loans at different rates, put any extra payments toward the highest-rate loan first (avalanche method) to minimise total interest paid.
- ✓Check whether your employer offers a student loan repayment benefit — as of 2026, employers can contribute up to $5,250/year tax-free to employee student loan payments under Section 127 of the tax code.
Official resources and further reading
Federal Student Aid — Loan Repayment Plans
The official StudentAid.gov guide to all federal student loan repayment plans — standard, graduated, extended, and income-driven options with eligibility requirements.
Consumer Financial Protection Bureau — Student Loans
The CFPB's official student loan guide covering repayment options, servicer disputes, and income-driven repayment plan comparisons.
IRS — Student Loan Interest Deduction
IRS guidance on the student loan interest deduction — up to $2,500 of student loan interest paid is deductible from federal taxable income, subject to income limits.
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Frequently asked questions
At 6.5% interest on a standard 10-year repayment plan, the monthly payment on $50,000 is approximately $567. Total interest paid over 10 years would be about $18,100. Extending to a 20-year plan reduces the payment to approximately $373/month but increases total interest to about $39,500.