Explain it like I'm 12
Student Loan Calculator applies fixed-payment amortising-loan maths, then tests how an optional extra monthly payment changes payoff time and total interest.
Student Loan Calculator
Estimate student loan monthly repayment, total interest and payoff timing from balance, annual rate, repayment term and optional extra monthly payment.
Source references
- Federal Student Aid - Loan Repayment — student loan repayment education reference
Formula
Base payment = P × r ÷ (1 − (1 + r)^−n). Total monthly payment = base payment + extra payment. Balance is reduced month by month until paid off.
Worked example
$32,000 over 10 years at 5.5% uses a monthly rate of 0.055 ÷ 12 and 120 scheduled payments. The base payment is about $347/month before any extra payment, then the calculator projects the balance month by month until payoff.
Professional note
Master’s Tip: even small extra payments can shorten the final months because they attack principal after required interest is covered.
Regional and unit assumptions
General amortising education-loan estimate. Local student-loan programs can use different statutory repayment rules.
Repayment proof
Balance, interest, payment
A student loan estimate is useful only when the monthly payment and payoff path are shown together. The page keeps the balance, fixed rate, repayment term and optional extra payment visible, then follows the balance month by month.
Visible checks
What the page now proves
- Fixed-payment formula
- Extra-payment payoff test
- Statutory/income-driven limits stated
Assumptions and limitations
- The rate is fixed and compounded monthly.
- Fees, income-driven repayment rules, deferment, subsidy and tax effects are not included.
- For Australian HELP/HECS loans, use the dedicated HELP repayment calculator instead.
Methodology & Accuracy
How this calculator is checked
CalculationTime pages are built around visible arithmetic: the formula, assumptions, worked example and practical limitations are shown so the result can be checked rather than simply trusted.
Formula used
Base payment = P × r ÷ (1 − (1 + r)^−n). Total monthly payment = base payment + extra payment. Balance is reduced month by month until paid off.
Standard or basis
General amortising education-loan estimate. Local student-loan programs can use different statutory repayment rules.
Where a calculator follows a named legal, trade or industry standard, that standard is cited visibly. Otherwise the page uses transparent general arithmetic and states its limits.Master's Tip
Master’s Tip: even small extra payments can shorten the final months because they attack principal after required interest is covered.
Related calculators
Questions
Does this match income-driven repayment?
No. It models a fixed-payment amortising loan. Income-driven or statutory repayment systems need separate rules.
What does extra payment change?
Extra payment reduces principal faster, usually lowering total interest and payoff time.