BYTETOOLS

Student Loan Calculator

Calculate monthly payments, payoff date and lifetime interest across one or several student loans, including interest that capitalizes during a grace period.

Your loans

$314.51
Total monthly payment
$9,883.09
Lifetime interest
$37,741.84
Total repaid
10 yr 6 mo from now
Paid off by

Per-loan breakdown

LoanCapitalisedPrincipalMonthlyInterest
Subsidised loan$330.00$12,330.00$133.81$3,727.55
Unsubsidised loan$528.75$15,528.75$180.70$6,155.54

A standard level repayment plan at a fixed rate. Income-driven plans, forgiveness programmes, subsidised interest and origination fees are not modelled. Estimates only, not financial advice.

What is the Student Loan Calculator?

The ByteTools Student Loan Calculator works out what your education debt really costs. Add each loan with its balance, interest rate and repayment term, and the tool amortizes every loan separately before combining them into a single monthly payment, payoff date and lifetime interest figure.

  • Unlimited loans, each with its own balance, rate and term
  • Grace-period interest accrual with optional capitalization
  • Combined monthly payment plus a per-loan breakdown
  • Total interest, total repaid and payoff date for the whole portfolio
  • Per-loan interest column so you can see which loan costs the most
  • 100% local — balances never leave your device

How to use the Student Loan Calculator

  1. 1

    Add a row for each student loan with its balance, interest rate and repayment term.

  2. 2

    Set the grace or in-school period in months, if any.

  3. 3

    Choose whether accrued interest capitalizes at the end of the grace period.

  4. 4

    Read the combined monthly payment, payoff date and total interest.

  5. 5

    Check the per-loan table to see which loan is costing you the most.

About the Student Loan Calculator

The ByteTools Student Loan Calculator works out what your education debt really costs. Add each loan with its balance, interest rate and repayment term, and the tool amortizes every loan separately before combining them into a single monthly payment, payoff date and lifetime interest figure.

Its key feature is the grace period. Interest usually keeps accruing while you study or during the months after graduation before repayment starts, and on unsubsidized loans that accrued interest is capitalized — added to the principal so you then pay interest on interest. Set the grace length and whether interest capitalizes, and the tool shows the real starting balance.

Everything runs locally in your browser and nothing is uploaded, so it is safe to enter real balances. Results are estimates for planning only, not financial advice — income-driven repayment plans, forgiveness programs and variable rates are not modelled here.

Frequently asked questions

How is a student loan payment calculated?

Standard repayment uses the same annuity formula as any other loan: payment = L × i ÷ (1 − (1 + i)^−n). A $30,000 balance at 5.5% over 10 years works out at about $325 a month. Each loan is calculated separately and the payments are added together.

What is student loan interest capitalization?

Capitalization is when unpaid interest accrued during school, a grace period or deferment is added to your principal balance. From that point you pay interest on the larger amount, which is why capitalized interest quietly raises the lifetime cost of the loan.

Does interest accrue while I am still in school?

On unsubsidized loans, yes — interest starts the day the loan is disbursed. On subsidized loans the government generally covers the interest while you are enrolled at least half-time and during the grace period. Set the grace period to zero to model a subsidized loan.

Should I pay off the highest-rate loan first?

Mathematically yes — targeting the highest interest rate first minimises total interest, which is the avalanche method. Some people prefer clearing the smallest balance first for the motivation. The per-loan table shows you which loan carries the most interest.

Does this cover income-driven repayment or forgiveness?

No. This models standard fixed amortization only. Income-driven plans recalculate your payment from your income and family size each year, and forgiveness rules change frequently, so those cannot be estimated reliably from a static formula.

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