Student Loan Payoff Calculator: Time and Interest to Clear It
See how long a student loan takes to clear at a chosen monthly payment, and how much interest a larger payment would save.
Adjust the inputs and select Calculate for a full breakdown.
Year-by-year payoff schedule
Compare Common Scenarios
How the numbers shift across typical situations for this calculator:
| Scenario | Time to pay off | Total interest | Total paid |
|---|---|---|---|
| $35k · 6.5% · $400/mo | 9y 11m | $12,565.36 | $47,565.36 |
| $20k · 5.5% · $300/mo | 6y 8m | $3,922.34 | $23,922.34 |
| $60k · 7% · $700/mo | 10 years | $23,420.32 | $83,420.32 |
| $12k · 4.5% · $250/mo | 4y 6m | $1,254.86 | $13,254.86 |
How This Calculator Works
Enter the loan balance, its interest rate, and the monthly payment you plan to make. The calculator works month by month — adding interest, subtracting the payment — until the balance clears, then reports the payoff time and the total interest.
The Formula
Debt Payoff Time
B = balance, P = fixed monthly payment, r = monthly rate (APR ÷ 12), n = months to clear
Worked Example
A $35,000 student loan at 6.5% paid at $400 a month clears in 119 months — just under ten years. Interest over that time comes to about $12,565, on top of the amount borrowed.
Key Insight
Extra payments applied to principal shorten a student loan sharply, because the remaining balance accrues less interest every month after. Confirm with the servicer that overpayments reduce principal, not future installments.
When aggressive payoff makes sense — and when it's wrong
Aggressive student loan payoff (paying more than minimum to eliminate quickly) makes sense IF: rate is high (7%+), you don't qualify for PSLF, you're far from any forgiveness threshold, and you have no high-interest debt or unmet 401(k) match. For these borrowers, every extra $100/month saves $200-400 in interest over the loan life.
Aggressive payoff is WRONG when: you qualify for PSLF (paying extra LOSES forgiveness money — make minimum IDR payments only), you're on income-driven repayment heading toward forgiveness in 5-10 years (paying extra reduces eventual forgiveness amount), or you have higher-priority financial gaps (no emergency fund, no employer 401k match, high-interest credit card debt).
Decision tree: (1) High-interest debt elsewhere (CC, personal loans)? Pay those first. (2) PSLF eligible? Pay minimum, save the rest. (3) Other IDR with forgiveness? Calculate tax bomb savings vs aggressive payoff — usually still favorable to ride IDR. (4) None of above + private/refinanced loans + rate >7%? Aggressive payoff wins. The category you fall into determines the right answer, not generic 'pay off debt fast' advice.
Refinancing federal to private: the one-way door
Refinancing federal student loans to private (SoFi, Earnest, CommonBond, LendKey) can lower rates 1-3 percentage points for high-credit-score borrowers in stable jobs. But you PERMANENTLY lose: IDR access, PSLF eligibility, deferment/forbearance options, death/disability discharge, future forgiveness programs.
Worked example: $80k of federal loans at 7% average ($930/month standard 10-yr payment). Refinanced to private at 5% = $848/month, saving $82/month or ~$9,800 over the life. Now: lose job in year 3 — federal would offer forbearance + IDR, private offers limited forbearance and then default. The $9,800 savings vanishes against the financial damage of a single career setback.
When refinancing IS right: stable high-income borrower (doctors, lawyers, engineers in their 30s), no public service plans, large rate reduction (2%+), able to weather job loss with savings. Refinancing private-to-private (lowering an already-private loan's rate) carries less risk — you're not giving up federal protections you had before. Refinance federal loans only if you're certain about the trade-offs.
Extra payment targeting: hit highest rate or specific loan?
Federal student loans come as multiple separate disbursements (one per semester typically) at the rate prevailing each year. You may have 8-12 small federal loans each with slightly different rates. Strategy matters.
Avalanche approach (mathematical optimum): target the HIGHEST rate loan first while paying minimums on the others. With multiple federal loans, this typically means targeting graduate Direct PLUS (8.94%) before undergraduate Direct Subsidized (6.39%).
Practical optimization: request that extra payments be applied 'to the highest rate loan' specifically. Without this request, servicers (especially Nelnet, MOHELA, Aidvantage) often apply extra payments PROPORTIONALLY across all loans — diluting the avalanche effect. Send a written instruction with each extra payment. Some servicers allow setting a default targeting preference in your account.
Extra monthly payment impact on $50k student loan (7% APR, 10-year term)
Standard 10-year payment on $50,000 at 7%: $581/month. How extra payments accelerate payoff.
| Extra payment | Payoff time | Total interest | Months saved |
|---|---|---|---|
| $0 (standard) | 120 months (10 yr) | $19,683 | 0 |
| $50/month | 108 months | $17,275 | 12 mo (1 year) |
| $100/month | 98 months | $15,486 | 22 mo |
| $200/month | 84 months (7 yr) | $12,756 | 36 mo (3 years) |
| $400/month | 65 months | $9,328 | 55 mo (4.6 years) |
Every $100/month extra payment saves roughly $4,000-5,000 in interest. Doubling the payment from $581 to ~$1,000 cuts loan term nearly in half. Verify your servicer applies extras to principal, not future payments.
Frequently Asked Questions
How can I pay off a student loan faster?
Raise the monthly payment, and direct any extra to principal. A larger payment cuts both the payoff time and the total interest noticeably.
Does this model income-driven repayment?
No. Income-driven plans set the payment from income rather than the balance. This calculator assumes a fixed monthly payment, suiting standard or accelerated repayment.
Should I pay extra or invest instead?
Compare the loan rate against the return you could expect investing. Paying down a high-rate loan is a guaranteed return; a low-rate loan is a closer call.
Will extra payments go to principal?
Not automatically. Some servicers apply overpayments to future installments. Instruct the servicer to apply anything extra to the principal balance.
What balance should I enter?
Use the current outstanding balance, including any capitalized interest, so the payoff time is measured from where the loan stands today.
References & Authoritative Sources
- CFPB — Consumer Financial Protection Bureau — Student loan repayment and payoff guide · consulted May 31, 2026 · Federal consumer protection — payoff strategy guides, servicer complaint handling
- Federal Student Aid — Repayment plans and extra payment handling · consulted May 31, 2026 · Official guidance — how to target extra payments to highest-rate loans
- Federal Reserve Bank of New York — Quarterly Household Debt Report — Student loan default statistics · consulted May 31, 2026 · Authoritative source — student loan delinquency rates, default patterns
Related Calculators
Data Sources & Benchmarks
This calculator draws on 3 independent, dated sources.
Methodology & Review
The payoff is simulated month by month from the current balance: interest is charged, the fixed payment is deducted, and months are counted until the balance clears. Income-driven plans are not modeled.
Updated