Student Loan

What Interest Adds Before You Start Paying

On unsubsidized loans the balance grows for years before the first payment is due. This calculator shows exactly how much, and what it costs you over the full term.

Your loans

$

Total disbursed, before any accrued interest.

%

Federal rates are fixed and set annually. Check your servicer or StudentAid.gov for your exact rate.

yr
mo
$
Monthly payment
$—
per month
Amount borrowed
Interest before repayment
Balance at first payment
Interest during repayment
Total repaid
Payoff time

What capitalization costs

On an unsubsidized loan, interest starts accruing the day the money is disbursed — not the day you graduate. Nobody bills you for it while you are enrolled, so it accumulates quietly. When you enter repayment, that accumulated interest is added to your principal. This is capitalization, and from that moment you are paying interest on interest.

The practical result is that many borrowers make their first payment on a balance noticeably larger than the amount they signed for. The table below compares letting that happen against paying the interest as it accrues.

Capitalized interest
Lifetime cost of capitalizing
Interest-only payment in school
Both paths assume the same rate and repayment term. The interest-only path assumes you pay exactly the interest accruing each month while enrolled and during the grace period, so the principal never grows. Subsidized federal loans accrue no interest during these periods, so the two paths are identical for them.
Approach Paid before repayment Starting balance Monthly Total paid
Why in-school interest payments punch above their weight: the amount is small each month, but every dollar you pay then is a dollar that never enters your principal — so it never earns interest against you for the following ten to twenty five years. Switch the dropdown above between the two options and compare the total repaid.

What each repayment term costs

Extending the term lowers the monthly payment, which can be necessary. It is worth seeing the price of that relief before choosing it.

Calculated from your starting balance after capitalization. Federal income-driven plans are not modelled here because payments depend on income and family size rather than balance alone.
Plan Monthly Total interest vs 10 years

Payment schedule

# Payment Principal Interest Balance

How student loans differ from other debt

Subsidized versus unsubsidized

This single distinction accounts for most of the difference in what two borrowers with identical balances end up paying. On a subsidized federal loan the government covers the interest while you are enrolled at least half time, during the grace period, and during approved deferment. On an unsubsidized loan nothing is covered. Set the loan type above to each in turn and compare the balance at first payment.

Repayment plans are not just about the payment

Extending from ten years to twenty five roughly halves the monthly payment, which for many borrowers is the difference between manageable and not. But it also means paying interest for fifteen additional years on a balance that comes down slowly. The term comparison above prices that trade-off with your own numbers.

Forgiveness changes the arithmetic entirely

If you are pursuing Public Service Loan Forgiveness or forgiveness under an income-driven plan, the usual advice to pay extra is backwards. Extra payments reduce the balance that would eventually be forgiven, so you are paying down debt someone else would have absorbed. This calculator models straightforward amortization and does not account for forgiveness — if it applies to you, the numbers here are the wrong frame.

Federal rules change

Repayment plan names, eligibility and terms have been revised repeatedly, including changes to income-driven plans and forgiveness programs. Anything you read about specific federal plans, here or elsewhere, should be checked against the current rules at StudentAid.gov, which is the official source. For complaints or problems with a servicer, the CFPB's student loan resources are the place to start.

Private loans

The accrual and capitalization mathematics are identical, but private loans have no subsidized option, no access to federal income-driven repayment or forgiveness, and frequently carry variable rates that can rise over the life of the loan. Grace period and deferment terms are set by the lender, so read the promissory note rather than assuming federal rules apply.

This page is an educational calculator, not financial advice, and does not model income-driven repayment or loan forgiveness. Federal loan terms and repayment programs change; verify current rules at StudentAid.gov before making decisions. Your actual rate and terms come from your promissory note and servicer.

Questions people ask about student loans

What is capitalization?

The moment unpaid accrued interest is added to your principal balance. From then on you pay interest on that interest.

It typically happens when you enter repayment after the grace period, and on some loans when deferment or forbearance ends. It is why the balance at your first payment can be larger than the amount you borrowed.

Subsidized or unsubsidized — what's the difference?

On a subsidized federal loan the government pays the interest while you are enrolled at least half time, during the grace period, and during approved deferment. On an unsubsidized loan interest accrues from the day of disbursement, including every year you are in school.

Over four years of study plus a six-month grace period, that gap commonly runs into thousands of dollars added before your first payment.

Should I pay interest while still in school?

If you have unsubsidized or private loans and can afford it, yes. The monthly amount is comparatively small, and it stops that interest from capitalizing into the principal you will carry for the next decade or more.

The comparison table above shows the lifetime difference for your specific numbers.

Which repayment plan should I choose?

Standard ten-year produces the lowest total interest. Extended plans lower the monthly payment and raise the total substantially. Income-driven plans cap payments as a share of discretionary income and can end in forgiveness, which changes the calculation entirely for high balances relative to income.

Federal plan rules have changed repeatedly — confirm what is currently available at StudentAid.gov rather than relying on any third-party summary, including this one.

Pay off early, or invest instead?

There is no prepayment penalty on federal loans, and extra payments cut total interest. Which is better depends on your rate: at higher rates, the guaranteed return from paying down debt is hard to beat; at low rates the case for investing is stronger, though not guaranteed.

One firm exception: if you are pursuing forgiveness, extra payments reduce the amount that would have been forgiven.

Do private loans work the same way?

The accrual and capitalization mathematics are the same. What differs is everything around it: no subsidized option, no federal income-driven repayment or forgiveness, and often a variable rate that can rise. Grace and deferment terms are whatever the lender wrote into your promissory note.

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