Student Loan Interest Calculator
Interest is the quiet half of your student loan payment. Enter your loan below to see the total interest you'll pay over its life — and how much of it extra payments can erase.
Yearly amortization (with extra payments)
| Year | Principal paid | Interest paid | Remaining balance |
|---|
How student loan interest actually works
Student loans use simple daily interest. Your annual rate is divided by 365, charged on your balance every day, and your monthly payment covers that interest first — whatever is left pays down principal. Early in the loan, interest eats most of your payment; that's why the first years feel like standing still.
Daily interest cost = (balance × rate) ÷ 365. On a $37,000 loan at 5.8%, that's about $5.88 every single day — before any principal.
Why the totals above are so large
On a standard 10-year plan at 5.8%, a $37,000 loan accrues roughly $11,800 in interest — about 32% of everything you borrowed. The green numbers in the calculator show how much of that a modest extra payment removes: interest saved compounds monthly because each dollar of principal you kill early stops charging interest for the rest of the term.
This calculator is for educational purposes only and is not financial advice. Actual interest depends on your servicer's exact day-count conventions; check your statement or studentaid.gov for official figures.