Student Loan Calculator
Price a student loan on the standard schedule, compare it against an income-driven payment, and see what a modest overpayment removes from the term.
Student Loan Calculator
Results recalculate instantly on every keystroke. Nothing you type is transmitted.
What this result does not account for
- Results are a model, not a quotation — an institution's own figures govern.
- Every input is an assumption; change one and the answer changes with it.
- Rounding is applied only at the display layer, so totals may differ by a cent from a statement that rounds each line.
In short: Federal student loans default to a ten-year standard schedule. A $38,000 balance at 6.53% costs $432.06 a month and $13,847.51 in interest — but adding $150 a month clears it in 6 years 9 months and saves $4,772.40.
Formula
Income-driven plans ignore the balance entirely; the payment depends only on income and household size, which is why large balances and modest incomes diverge so sharply.
Worked Example
- Standard payment. $38,000 at 6.53% over 120 months = $432.06.
- Total the interest. $432.06 × 120 − $38,000 = $13,847.51.
- Add $150 a month. The balance clears after 81 payments — 6 years 9 months.
- Value the acceleration. Interest falls to $9,075.11, saving $4,772.40.
- Compare income-driven. 10% of $29,410.00 discretionary income is $245.08 a month.
Analyst note. The income-driven payment is $186.98 lower, which is genuine relief but not a saving: at $245.08 against $206.72 of monthly interest in year one, the balance barely moves. Income-driven plans are a cash-flow instrument with a forgiveness backstop, not a cheaper way to repay. If you can afford the standard payment, the $150 overpayment is the better use of the same money.
Strengths & Limits Of This Model
Where this engine is strong
- Runs entirely in your browser — no figure you type is transmitted or stored.
- Shows the full working, so every number can be traced and challenged.
- Free, unmetered and free of affiliate incentives.
Where it stops
- Generalised assumptions cannot capture every individual circumstance.
- Jurisdiction-specific rules and mid-year changes may not be reflected.
- A model output is not a substitute for a professional review of your position.
Practical Use Cases
Deciding between standard and income-driven repayment
The gap of $186.98 a month is real, but so is the interest that continues accruing. Compare against other obligations with the Debt To Income Calculator.
Testing what a small overpayment achieves
$150 a month removes 39 payments and $4,772.40. Few uses of $150 return that reliably, and the Student Loan Payoff Calculator shows how to sequence it across several loans.
Planning around a mortgage application
Lenders count the student loan payment against your ratios, so the plan you choose directly affects borrowing capacity. Model both with the Mortgage Affordability Calculator.
Methodology & Editorial Standards
The standard payment is a level amortising annuity over the selected term, which matches how federal servicers calculate the standard and extended plans. The income-driven figure applies the common formula of ten percent of discretionary income, defined as adjusted gross income less 150% of the federal poverty guideline for the household size, divided by twelve; plan rules vary and some use different percentages or thresholds, so the guideline is an editable input. Interest capitalisation, subsidised interest benefits during deferment, and forgiveness after twenty or twenty-five years are not modelled, since each depends on plan type and legislative changes. The overpayment scenario assumes extra amounts are applied to principal, which requires explicit instruction to most servicers. The engine implements the standard published formula for this calculation. Inputs are validated for domain and sign before evaluation, and any undefined case returns an em-dash rather than a spurious value.
Computation runs in IEEE-754 double precision at full internal precision; rounding to two decimal places occurs strictly at the display layer, so no cumulative drift enters the result. All monetary outputs use accounting presentation — grouped thousands, two decimals, negatives in parentheses — so figures can be transcribed directly into a model or working paper. Division-by-zero and out-of-domain inputs return an em-dash rather than a misleading number.
This engine was reconciled against an independent reference implementation and hand-verified for the worked example above before release. Our full five-stage review process is published on the About Us page.
Disclaimer. This calculator is provided for informational and modelling purposes only and does not constitute financial, tax, legal, medical, or engineering advice. Verify all figures with a qualified professional before acting on them.
Student Loan Calculator — 20 Expert FAQs
20 analyst-written answers to the questions practitioners actually ask — optimised for voice and answer-engine retrieval.
How much is my student loan payment?
On the standard ten-year plan, a $38,000 balance at 6.53% costs $432.06 a month. The plan you choose matters more than the balance for monthly cash flow.
Is income-driven repayment cheaper?
Lower monthly, not cheaper. $245.08 against $432.06 frees $186.98 a month, but with roughly $206.72 of interest accruing monthly in year one, the balance barely moves.
How is discretionary income calculated?
Adjusted gross income less 150% of the federal poverty guideline for your household size. On $52,000 against a $15,060 guideline, that is $29,410.00, and ten percent of it is the annual payment.
Should I pay extra on student loans?
If the rate exceeds what you would earn elsewhere, yes. $150 a month here removes 39 payments and $4,772.40 of interest — a strong, certain return.
Will extra payments go to principal automatically?
Often not. Many servicers apply overpayments to future instalments instead, which advances your due date without reducing interest. Instruct them in writing to apply extras to principal.
What happens to interest under income-driven plans?
It continues accruing, and if the payment is below the interest charge the balance grows. Some plans subsidise part of the unpaid interest; others capitalise it, which is materially worse.
Is student loan forgiveness worth planning around?
Public Service Loan Forgiveness after ten years of qualifying payments is well established. Broader forgiveness has been legally contested, so plan on repaying and treat forgiveness as upside.
Should I refinance federal loans privately?
Only with caution. A lower rate is attractive, but refinancing federally-held debt privately permanently surrenders income-driven plans, forbearance rights and forgiveness eligibility.
Do student loans affect my mortgage application?
Yes, directly. Lenders count the monthly payment in your debt-to-income ratio, and some use a percentage of the balance where the payment is zero under an income-driven plan.
What is the difference between subsidised and unsubsidised?
The government pays interest on subsidised loans while you are enrolled and during deferment. Unsubsidised loans accrue throughout, and that interest capitalises into the balance at repayment.
Is a longer repayment term ever sensible?
It lowers the payment but raises total interest substantially. It is defensible as a temporary cash-flow measure, and poor as a long-term plan if you can afford more.
Can I deduct student loan interest?
Up to a capped amount annually, subject to income phase-outs, and it is available whether or not you itemise. The benefit shrinks as income rises and disappears entirely above the threshold.
Is this student loan calculator free to use?
Yes. It is free, requires no account, and has no usage limits. ApexConverter is funded by contextual advertising, never by selling user data.
Is my data sent to a server?
No. The engine runs as Vanilla JavaScript inside your browser under our Zero-Server Client-Side Execution model. Your figures are computed locally and are never transmitted, logged, or stored.
How accurate is this calculator?
It applies the standard closed-form formula in IEEE-754 double precision, rounding only at the display layer. The engine is reconciled against an independent reference implementation before release.
Does it work on mobile?
Yes. The interface is mobile-first with numeric keypad hints and is tested down to a 320-pixel viewport with no horizontal scrolling.
Can I use it offline?
Largely, yes. Because computation is client-side, the page continues to calculate without a network connection once it has loaded.
Which currency does it use?
Amounts display in US$ accounting format, but the underlying mathematics is currency-agnostic. The result is identical in any currency, so simply read the figures in your own.
Why does a result show an em-dash?
An em-dash indicates the calculation is not defined for the inputs given — typically a division by zero or a value outside the valid domain. We show a dash rather than a misleading number.
How do I report an error?
Email apexconverter.praxiscalc@gmail.com with the tool URL, your exact inputs, the output received and the output you expected. Verified mathematical errors are patched within 72 hours.