Loans
Student Loan Calculator
Know your student debt's real shape. Enter your balance, rate, and repayment term to see the monthly payment, total interest, and payoff date under standard repayment — then add an extra monthly amount and watch years disappear from the timeline.
Tested against worked examplesHow we verify
The average US bachelor's borrower graduates with roughly $30–40k.
Federal undergrad loans disbursed 2025–26 carry ~6.4%; grad and private rates run higher.
Monthly payment: $431.48
Monthly payment
$431.48
- Total interest
- $13,778
- Total repaid
- $51,778
- Debt-free in
- 10 years
Balance by year
| Year | Principal paid | Interest paid | Balance |
|---|---|---|---|
| 1 | $2,790 | $2,388 | $35,210 |
| 2 | $2,977 | $2,201 | $32,233 |
| 3 | $3,176 | $2,002 | $29,057 |
| 4 | $3,389 | $1,789 | $25,668 |
| 5 | $3,616 | $1,562 | $22,053 |
| 6 | $3,858 | $1,320 | $18,195 |
| 7 | $4,116 | $1,061 | $14,078 |
| 8 | $4,392 | $786 | $9,686 |
| 9 | $4,686 | $492 | $5,000 |
| 10 | $5,000 | $178 | $0 |
Compare scenariosTry three values of one input
| Loan balance | |||
|---|---|---|---|
| Monthly payment | $386.06 | $431.48+$45.42 | $476.90+$90.84 |
| Total interest | $12,328 | $13,778+$1,450 | $15,228+$2,900 |
| Total repaid | $46,328 | $51,778+$5,450 | $57,228+$10,900 |
Every other input stays at the value you set above — currently $38,000 for loan balance. Differences are measured against the first column.
Saved scenariosSave this calculation
Saved in this browser only — no account, and nothing is sent to us. Clearing your browser data deletes them.
How this calculator works
Payments follow standard amortization in exact cents; extra payments apply fully to principal in the month paid. The savings figures compare your schedule against the same loan without extras, computed with identical rounding.
Income-driven repayment, capitalized interest events, and forgiveness programs are out of scope for this tool. For federal borrowers weighing IDR plans, run the official simulator at StudentAid.gov as well.
What this assumes
- A standard fixed repayment schedule. Federal loans offer income-driven plans that behave completely differently.
- Interest accrues from disbursement on unsubsidised loans, including during study and grace periods.
- Forgiveness programmes, deferment and forbearance are not modelled and change the outcome substantially where they apply.
What changes this number
- Extra payments
- Federal loans have no prepayment penalty, so anything above the minimum reduces the balance directly — but tell the servicer to apply it to principal.
- Rate
- Federal rates are set by statute and fixed at disbursement; private rates are priced to credit and may be variable.
- Repayment plan
- The largest fork in the road. Standard, graduated and income-driven plans produce entirely different totals.
A worked example
Take the average grad: $38k at 6.5%, 10 years scenario. These figures are produced by the calculator above, not written alongside it, so they always match what the tool returns.
What you enter
- Loan balance
- $38,000
- Interest rate
- 6.5%
- Repayment term
- 10 years
- Extra monthly payment
- $0
What it returns
- Monthly payment
- $431.48
- Total interest
- $13,778
- Total repaid
- $51,778
- Debt-free in
- 10 years
Try an example
Frequently asked questions
What is standard repayment?
The default federal plan: fixed payments over 10 years. It costs the least total interest of the traditional plans and is what this calculator models. Income-driven plans lower the payment by stretching the term (and usually raising lifetime interest, absent forgiveness).
Should I pay extra on student loans or invest?
Compare your loan rate to realistic after-tax investment returns. Rates above ~6–7% make prepayment a strong guaranteed return; low-rate loans (under ~4%) often lose to long-run investing. Emotion counts too — being debt-free has real value no spreadsheet captures.
Do extra payments go to principal automatically?
Not always — some servicers apply extra money to future payments ('paid ahead') instead of principal, which saves you nothing. Instruct your servicer in writing to apply overpayments to principal on your highest-rate loan, then verify on the next statement.
Can student loans be refinanced?
Private refinancing can cut the rate for strong-credit borrowers — but refinancing FEDERAL loans forfeits income-driven plans, deferment protections, and any forgiveness eligibility permanently. Refinance private loans freely; refinance federal ones only with eyes open.
Is student loan interest tax-deductible?
Up to $2,500 a year of interest is deductible 'above the line' subject to income phase-outs — worth checking each filing season. The deduction softens the effective rate slightly but doesn't change the payoff math here.
Related calculators
Debt Payoff Calculator — Snowball vs Avalanche
Enter up to three debts and compare the snowball and avalanche strategies head-to-head: payoff dates, total interest, and what the difference costs.
Loan Calculator
Calculate the monthly payment, total interest, and payoff date for any personal, auto, or fixed-rate loan — and see how extra payments shorten it.
50/30/20 Budget Calculator
Split your after-tax income the 50/30/20 way — needs, wants, savings — with monthly dollar targets and the yearly savings it produces.
Disclaimer: DayCents provides this calculator for educational purposes only. Results are estimates based on your inputs and the stated assumptions — they are not financial advice, a quote, or an offer of credit. Consult a qualified financial professional before making major money decisions.