Student Loans

What does capitalized interest actually cost me?

Interest that accrues while you are not paying is owed either way. What costs extra is the moment it joins your principal and starts earning interest of its own. This separates the two.

What was disbursed, before anything accrued.
6.52% is the 2026-27 undergraduate rate.
On a Direct Loan today, a deferment on an unsubsidized loan capitalizes and a forbearance does not.
What capitalizing costs you$0.00

You accrued $7,921.80 of interest and still owe it. But it stays outside your principal, so it never earns interest of its own, and capitalization costs you nothing.

  • $7,921.80Interest accrued, owed either way
  • $0.00Amount that joined your principal
  • $34,921.80Balance repayment starts from
  • $44,744.32Total paid, with capitalization
  • $44,744.32Total paid, without it
  • $372.87Monthly payment, with capitalization
What the balance does before the first payment is due
PeriodMonthsInterest accruedOwed at the end
In school48$7,041.60$34,041.60
Grace period6$880.20$34,921.80

What capitalization is, in one paragraph

While you are not making payments, interest accrues. It is owed. But on a federal loan it sits outside your principal, and money outside the principal does not earn interest. Capitalization is the moment it moves inside. From then on you are paying interest on interest, and that is the only thing capitalizing costs you. The accrued interest itself was always going to be owed.

This matters because the two figures get confused constantly. If you accrued $6,000 of interest during four years of study and it capitalizes, the cost of capitalizing is not $6,000. It is the extra interest that $6,000 earns over the rest of your loan, which on a ten-year term at 6.52% is closer to $2,300.

It happens far less often than people think

Regulations that took effect on 1 July 2023 removed most of the triggers. A Direct Loan now capitalizes on exactly two events: the end of a deferment on an unsubsidized loan, and leaving Income-Based Repayment or ceasing to qualify for an income-based payment under it. That is the whole list.

Leaving a forbearance no longer capitalizes. Neither does the end of the grace period, nor entering repayment, nor defaulting. Those all used to, and a great deal of advice written before 2023 still says they do.

Two caveats. The change was not retroactive, so anything capitalized before July 2023 is in your principal permanently. And it applies to loans the Department holds. A FFEL loan held commercially is still on the old rules, where forbearance and the end of grace both capitalize.

What this calculator assumes

Interest accrues daily on a 365.25-day year, which is the formula the Department publishes, and it accrues on the principal only. Months are treated as equal twelfths of a year rather than as real calendar months, so a figure here can differ from your servicer's by a few dollars over a term.

Sources

  1. Interest rates and fees for federal student loans, U.S. Department of Education. Checked on . Backs the two capitalization triggers on Direct Loans and Department-held FFEL loans; the four triggers on FFEL loans not held by the Department; the daily interest formula and its 365.25-day year; the worked example of a deferment on a $10,000 loan at 6.8%.
  2. How does interest accrue while I am in school?, Consumer Financial Protection Bureau. Checked on . Backs that private loan capitalization is set by contract rather than by regulation.
  3. Regulation Z, section 1026.47, private education loan disclosures, Consumer Financial Protection Bureau. Checked on . Backs the disclosure requirement at application, approval and consummation.

The rules behind this calculator were last checked on .

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