Student Loan Calculator
Monthly payment, total paid, and interest for student loans at fixed rates.
What it does
A student loan amortizes like any fixed rate loan: equal monthly payments cover interest first with the rest cutting principal. Early payments are mostly interest, late ones mostly principal, while the check stays flat throughout.
The tool above takes the balance, annual rate, and repayment years. It returns the monthly payment with lifetime totals for the full standard schedule.
The default of $30,000 at 6.8% over 10 years pays $345.24 a month, totaling $41,428.92 with $11,428.92 interest. Stretching to 20 years would drop the payment near $230 but roughly double the interest.
Federal loan guidance from Federal Student Aid and CFPB student resources both stress the same extras beyond this math: income driven plans, grace periods, autopay discounts, and forgiveness paths that private refinancing usually removes.
How to use
- Enter the total balance borrowed, before fees.
- Enter the fixed annual rate from the loan note.
- Enter the repayment term in years.
- Read the monthly payment first for budget fit.
- Compare total interest across terms before signing.
Formula
- P
- Balance borrowed at the start.
- r
- Monthly rate: annual divided by 12.
- n
- Total monthly payments: years times 12.
Zero interest reduces to balance divided by months. Variable rates, grace period interest, origination fees, and income driven recalculations sit outside this fixed schedule.
Worked example
Example: $30,000 at 6.8% for 10 years
Balance 30000, rate 6.8%, term 10 years (120 months).
- Monthly rate: 0.068 / 12 = 0.0056667.
- Growth factor: (1.0056667)^120 = 1.96996.
- Payment: 30000 x 0.0056667 x 1.96996 / 0.96996 = $345.24.
- Total: 345.24 x 120 = $41,428.92.
- Interest: 41,428.92 - 30,000 = $11,428.92. Tool shows all three.
Reference table
| Term | Monthly | Total interest |
|---|---|---|
| 10 years | $345.24 | $11,428.92 |
| 15 years | $266.31 | about $17,935 |
| 20 years | $229.00 | about $24,960 |
| 25 years | $208.22 | about $32,466 |
Limits
- Fixed rate schedule only; variable rates move payments.
- Ignores fees, grace interest, and income driven plans.
- Extra payments shorten the term beyond this table.
- Tax deduction rules change and need current IRS guidance.
Common mistakes
- Comparing loans by monthly payment instead of total interest.
- Refinancing federal loans private without weighing lost protections.
- Ignoring unsubsidized interest growing during school.
- Deferring without checking what still accrues.
- Borrowing the maximum offered instead of the budgeted need.
Try it yourself
Quick checks. Answers sit tucked under each question.
$10,000 at 5% for 5 years?
$188.71 a month, $11,322.74 total, $1,322.74 interest.
Payment per $10,000 at 6.8% for 10 years?
About $115.08 a month (345.24 / 3).
Interest share first payment above?
30000 x 0.0056667 = $170.00 interest, $175.24 principal.
Questions
What is the monthly on $30,000 at 6.8%?
$345.24 over 10 years, totaling $41,428.92.
How is student loan interest set?
Federal undergraduate rates are fixed yearly by law; private rates vary by credit.
Does a longer term help?
It cuts the payment but raises lifetime interest substantially. Compare both columns.
What happens in grace periods?
Subsidized loans pause interest; unsubsidized keep accruing and capitalize after.
Should I refinance federal loans?
Only after weighing income plans, deferment, and forgiveness that refinancing removes.
Do extra payments help?
Yes. Anything above the schedule cuts principal directly and shortens the loan.