Student loans: subsidized, unsubsidized, and the interest clock
Federal student loans aren't all equal. Knowing which type you have can save (or cost) you thousands.
The three main federal flavors
- •Direct SUBSIDIZED — for undergrads with financial need. The government pays the interest while you're in school.
- •Direct UNSUBSIDIZED — open to anyone. Interest accrues from day one, even while you're in classes.
- •Direct PLUS — for grad students or parents. Higher rate, no subsidy, full interest accrual.
$10,000+
Hidden interest on $30K unsub loans
Four years of unsubsidized interest at ~6.4% (the 2025–26 federal undergrad rate) adds roughly $7K–$10K to your balance BEFORE your first payment.
When you leave school, accrued interest 'capitalizes' — it gets added to your principal. From then on, you're paying interest on the interest.
If you can swing $30–$80/month during school, even just on unsubsidized loans, you can prevent thousands in capitalized interest.
Run your real numbers
Plug in your balance, rate, and payoff term to see total interest paid — and what that same monthly payment could be worth invested instead.
Monthly payment
$340.64
Total interest
$10,877
Invested @ 7%
$58,960
Estimated payoff date
Jun 2036
Based on the term you set above. Extra payments would move this date earlier.
On a $30,000 loan at 6.50% over 10 years, you'd pay $10,877 in interest. That same monthly payment, invested at 7% for the same 10 years, would grow to about $58,960. That gap is the real lifetime cost of this debt.
Estimate. Real federal loans may have fees, capitalized interest, or income-driven plans that change the math.
Real life: meet $30k of unsub at ~6.4%
A junior with $30k of unsubsidized federal loans (2025–26 undergrad rate ~6.4%) accrues ~$160/month in interest in school. Over 4 years that's ~$7,700 — added to the balance at graduation if not paid.
Accrues ~$7,800 in 4 years if unpaid
Takeaway
Use the Reality Check widget to see exactly what your loans cost in total interest — and what that monthly payment could have been worth invested.
Why do unsubsidized loans cost more long-term than subsidized?
Takeaway: Even small in-school interest payments prevent thousands of dollars of capitalized interest later.
Try together: Run the Student Loan Reality Check with the learner's real loan numbers. Compare total interest to the 'invested at 7%' figure.