About the Student Loan Calculator
This student loan calculator estimates the monthly payment and total cost of federal or private student loans on a fixed repayment schedule. Enter your balance, interest rate and repayment term — 10 years is the traditional federal Standard plan — and it shows the payment, total interest, how much interest accrues each day, and the salary you would typically want to keep the payment near 10% of gross income.
Add an extra monthly amount to see how much sooner you would be debt-free and how much interest you would save. The chart tracks your balance and cumulative interest year by year, and the table gives an annual amortization schedule.
If you have several loans, enter the combined balance and a weighted-average rate. Federal loans also offer income-driven plans that base payments on income instead of the balance; use the income-driven repayment calculator to compare those. This tool assumes a fixed rate and that repayment has already begun (no grace period or deferment).
With the default inputs, the monthly payment is $379.84. Change any value above to recalculate instantly.
How to use the student loan calculator
- 1Enter your total student loan balance.
- 2Enter the interest rate (or the weighted average of all your loans).
- 3Set the repayment term — 10 years for the federal Standard plan.
- 4Optionally add an extra monthly payment.
- 5Review the payment, total interest and payoff time, and compare terms.
Formula and method
Federal and most private student loans amortize like other installment loans: the monthly payment M repays the balance P at monthly rate r (annual rate ÷ 12) over n months. Federal Direct Loans accrue simple daily interest, so the interest building up each day is the balance × annual rate ÷ 365 — shown here as daily interest.
Extra payments are applied to principal after the month’s interest, shortening the schedule. The income guide multiplies the annual payment by 10, reflecting the common rule of thumb that student loan payments should stay around 10% of gross income.
- M
- Monthly payment
- P
- Loan balance
- r
- Monthly interest rate (annual rate ÷ 12)
- n
- Repayment term in months
Worked examples
$35,000 at 5.5% on a 10-year plan
A $35,000 balance at 5.5% over 120 months costs $379.84 a month and about $10,581 in interest. About $5.27 of interest accrues per day at the start, and keeping the payment near 10% of income implies a salary of roughly $45,600.
$60,000 at 6.5% over 20 years
Stretching $60,000 at 6.5% over 20 years keeps the payment to $447.34, but total interest climbs to about $47,362 — nearly as much as was borrowed.
Adding $100 a month to a $35,000 loan
Paying $479.84 instead of $379.84 each month on the default loan finishes in 89 months (7 years 5 months) instead of 120 and saves roughly $2,880 of interest.
Frequently asked questions
How is student loan interest calculated?+
Federal Direct Loans use a simple daily interest formula: balance × annual rate ÷ 365 × days since last payment. Each payment first covers accrued interest and the rest reduces principal. Most private lenders use the same approach.
What is the standard repayment plan for federal student loans?+
For loans made before July 1, 2026, the Standard plan uses fixed payments over up to 10 years (up to 30 years for Consolidation Loans), with a minimum payment of $50. Under the 2025 budget law, loans made on or after July 1, 2026 use a new standard plan whose term depends on the balance: 10 years under $25,000, 15 years up to $50,000, 20 years up to $100,000 and 25 years above that. Set the term field to match your plan.
Should I pay off student loans early?+
If your rate is above roughly 6%, paying extra is a strong guaranteed return. If you are pursuing Public Service Loan Forgiveness or an income-driven forgiveness plan, paying extra may not help, because the remaining balance could be forgiven.
Do student loans accrue interest during school?+
Direct Subsidized Loans do not accrue interest while you are in school at least half time or in the grace period. Unsubsidized and PLUS loans, and most private loans, accrue interest from disbursement, which may be capitalized when repayment begins.
How much student loan debt is too much?+
A common guideline is to borrow no more than your expected first-year salary, which keeps a 10-year payment around 10% of gross income or less. The “salary needed” result here shows the income that rule implies for your balance.
Results are estimates for educational purposes and are not financial advice. Rates, fees and terms vary — confirm with your lender or a licensed advisor before making decisions.