Student Loan Projection Calculator
Project total student debt for a current student still borrowing every year, including interest that accrues on each year's loan separately.
How to use this calculator
- 1Enter how much you expect to borrow each remaining year, and how many years of borrowing are left.
- 2Add any balance already borrowed from previous years, if this is not your first loan.
- 3Toggle whether interest accrues during school based on whether your loans are subsidized or unsubsidized.
How the calculation works
Balance at graduation = Σ (each tranche × monthly rate × its own months accruing) + total borrowed- Tranche
- Each year's new loan amount, disbursed once at the start of that school year
- Months accruing
- The specific tranche's own time until repayment — longer for money borrowed earlier
Every tranche is treated separately because each one has a different amount of time to accrue interest before repayment begins — combining them into a single lump sum at the average rate would understate the true balance.
Interest accrues as simple interest during deferment, matching how federal student loans actually work, then becomes a normal amortizing balance once repayment begins.
Worked example
$10,000 a year for 3 more years, unsubsidized, 6.5%, 6-month grace
- 1.Total borrowed: $10,000 × 3 = $30,000.
- 2.This year's $10,000 accrues for 3 years of school + 6 months grace = 42 months: $10,000 × (6.5%/12) × 42 = $2,275.00.
- 3.Year 2's $10,000 accrues for 2 years + 6 months = 30 months: $10,000 × (6.5%/12) × 30 = $1,625.00.
- 4.Year 3's $10,000 accrues for 1 year + 6 months = 18 months: $10,000 × (6.5%/12) × 18 = $975.00.
- 5.Total accrued interest: $2,275.00 + $1,625.00 + $975.00 = $4,875.00. Balance at graduation: $30,000 + $4,875.00 = $34,875.00.
Result: $34,875.00 owed at graduation
Why a still-borrowing student needs a different projection
The ordinary student loan calculator on this site assumes a single loan already fully disbursed, growing as one lump sum through deferment. A current student partway through school is in a genuinely different position: each year adds a brand new loan, and each of those loans has a different amount of time left to accrue interest before repayment starts. Money borrowed freshman year sits accruing interest for years longer than money borrowed senior year, even though both are due on the same first payment.
Why the first loan taken costs more than the last
Because interest is proportional to both the amount and the time it accrues, the very first tranche borrowed — typically freshman year — ends up carrying the largest interest burden of any single year's borrowing by the time repayment begins, even though every year borrowed the identical amount. This is a direct, mechanical consequence of accruing interest for a longer stretch, not a reflection of anything about that particular year's loan terms.
The subsidized-loan advantage, made concrete
The difference between a subsidized and unsubsidized federal loan is precisely the interest-accrual toggle this calculator exposes. A subsidized loan accrues no interest at all while in school or during the grace period — the government covers it — so the balance at graduation equals exactly what was borrowed. An unsubsidized loan of the identical size and rate can owe meaningfully more at graduation purely from accrued interest, which is why borrowing subsidized funds first, where eligible, is consistently recommended before turning to unsubsidized borrowing for the remainder.
What this assumes, and where it stops
Assumptions
- Each year's loan is disbursed once, at the start of that school year, rather than split across terms.
- The interest rate is the same across every year's tranche — in reality, federal loan rates are set annually and can differ from one year's borrowing to the next.
- Interest accrues as simple interest during deferment, consistent with how federal student loans actually work, and becomes a standard amortizing balance once repayment begins.
Limitations
- Does not model income-driven repayment plans or loan forgiveness programs.
- Real federal loan rates are set annually and commonly differ year to year — this projection holds a single rate constant across every year of borrowing.
Common questions
Why does the first year's loan cost more in interest than the last year's?
Because it has more time to accrue interest before repayment starts. A freshman-year loan sits accruing for the rest of school plus the grace period — several years — while a senior-year loan accrues for only a matter of months before the same first payment comes due.
What if my loans are a mix of subsidized and unsubsidized?
Run this calculator twice — once for the subsidized portion with interest accrual switched off, once for the unsubsidized portion with it switched on — and add the two balances at graduation together for the combined total.
Sources
- Federal student loan interest and capitalization — US Federal Student Aid
Formula and content last reviewed on .
Results are estimates for information only, not professional advice.
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