Finance & Money
Student Loan Calculator
Use this student loan calculator to find your monthly payment, total interest, and payoff time on a standard fixed-rate repayment plan, and to see how an extra monthly payment shortens the loan.
The balance you will repay, including any interest that capitalized during school or deferment.
6.53% is an example federal-style rate, not live data. Use the rate on your own loan.
The federal standard plan is 10 years. Extended plans run up to 25 or 30.
Optional. Any amount paid on top of the required payment, applied straight to principal.
Try an example
Result
Monthly payment
—
Required payment on the standard fixed-rate schedule, before any extra payment.
- Total paid
- —
- Total interest
- —
- Payoff time
- —
- Payoff with extra payment
- —
- Months saved
- —
- Interest saved
- —
More details (1 more)
- Total paid with extra payment
- —
Student quick launch
Grade planning, algebra checks, and formulas students reach for most.
Study path
Use this calculator with
Follow these when you want the formula behind the answer, a short lesson, or nearby tools in the same topic.
What this student loan calculator solves
It answers the three questions every borrower asks: what is the monthly payment, what does the loan really cost, and how long until it is gone? Enter the loan amount, annual rate, and term, and it returns the required monthly payment, total paid, total interest, and payoff time in months. Add an optional extra monthly payment and it also simulates the loan month by month to show the new payoff time, months saved, and interest saved.
The amortization formula
P is the loan amount, r is the monthly rate (annual rate divided by 12), and n is the number of monthly payments (years times 12). The formula finds the one fixed payment that covers each month's interest and still drives the balance to exactly zero at payment n. When the rate is 0%, there is no interest to amortize and the payment is simply P divided by n.
$30,000 at 6.53% over 10 years
Monthly rate: 6.53% / 12 = 0.005442. Payments: 10 x 12 = 120. Payment: M = 30,000 x 0.005442 / (1 - 1.005442^-120) = $341.10. Total paid: 341.10 x 120 = $40,932. Total interest: 40,932 - 30,000 = $10,932 - about a third of the original balance.
How extra payments shorten the loan
The required payment never changes on a standard plan, so every extra dollar goes straight to principal. A smaller principal accrues less interest the very next month, which lets more of each following payment hit principal too - the savings compound in your favor. The calculator does not approximate this; it walks the amortization schedule month by month with your boosted payment until the balance reaches zero.
| Extra monthly payment | Payoff time | Interest paid | Interest saved |
|---|---|---|---|
| $0 | 120 months | $10,932 | - |
| $50 | 100 months | $8,936 | $1,996 |
| $100 | 86 months | $7,567 | $3,365 |
| $200 | 67 months | $5,806 | $5,127 |
The table uses the default $30,000 loan at 6.53% over 10 years. Notice the pattern: the first $100 of extra payment saves more interest per dollar than the second $100, because the loan spends less time at a high balance either way. Any consistent extra amount helps; earlier and larger both help more.
How to use it
- Enter the total loan amount you will repay, including any capitalized interest.
- Enter the annual interest rate from your promissory note or loan servicer.
- Set the repayment term in years; the federal standard plan is 10 years.
- Add an optional extra monthly payment to see the new payoff time, months saved, and interest saved.
How to read the answer
The monthly payment is what a fixed-rate amortized loan requires each month so the balance reaches zero exactly at the end of the term. Early payments are mostly interest and later payments are mostly principal; any extra payment goes straight to principal, which is why even a small extra amount removes whole months from the back end of the loan.
Common mistakes and edge cases
- This models a fixed-rate standard repayment plan; income-driven plans (SAVE-style, IBR, PAYE) recalculate payments from income instead.
- The default 6.53% rate is an example federal-style rate, not live data; replace it with the actual rate on your loan.
- If you have several loans at different rates, run each loan separately instead of averaging the rates.
- Interest that capitalized during school or deferment belongs in the loan amount; leaving it out understates the payment.
- Servicers round payments to the cent and the final payment is usually smaller, so real statements can differ from this estimate by a few cents.
Worked examples
Standard 10-year federal-style plan
The default: $30,000 at an example 6.53% rate on the 10-year standard schedule gives a $341.10 payment and about $10,932 of interest.
Monthly payment
$341.10
Extra $100 per month
The same loan with $100 extra: the required $341.10 payment is unchanged, but the loan is gone in 86 months instead of 120, saving about $3,365 in interest.
Monthly payment
$341.10
0% interest loan
A $12,000 zero-interest loan over 5 years amortizes to a flat $200 per month with no interest cost.
Monthly payment
$200.00
Large balance on a 20-year term
$60,000 at 7.05% stretched to 20 years: a $466.98 payment, but total interest (about $52,076) approaches the original balance.
Monthly payment
$466.98
Loan amount of zero
There is nothing to amortize, so the calculator asks for a balance instead of dividing by zero.
Monthly payment
Error
Frequently asked questions
What is the standard student loan repayment plan?+
The federal standard plan is a fixed monthly payment over 10 years (120 payments). It is the default plan for federal loans and usually costs the least total interest among the fixed-payment federal options.
Does this calculator work for income-driven repayment plans?+
No. Income-driven plans (such as IBR, PAYE, or SAVE-style plans) recalculate the payment from your income and family size each year, so there is no fixed amortization schedule. This page models a fixed-rate, fixed-payment loan.
Where does the 6.53% default rate come from?+
It is an example federal-style rate used as a realistic starting point, not live data. Federal rates are set annually by Congress-linked formulas and private rates vary by lender and credit, so replace the default with the rate on your own loan.
How much does an extra $100 a month actually save?+
On the default $30,000 loan at 6.53% over 10 years, an extra $100 per month pays the loan off in 86 months instead of 120 and saves about $3,365 in interest. Enter your own numbers and the calculator simulates your exact schedule month by month.
Do extra payments lower my monthly bill?+
Not on a standard plan. The required payment stays the same; the extra amount reduces principal, which shortens the payoff time and cuts total interest instead. Ask your servicer to apply extra amounts to principal rather than advancing the due date.
Does the calculator include loan fees or capitalized interest?+
It amortizes exactly the loan amount you enter. To model your true starting balance, add any origination fee and any interest that capitalized during school, your grace period, or deferment to the loan amount.
About this calculator
- Written by
- mathcheck editorial team
- Last reviewed
- September 4, 2026
Method
- Models a fixed-rate loan on a standard amortized schedule; income-driven, graduated, and variable-rate plans are not simulated.
- The default 6.53% annual rate is an example federal-style rate for illustration, not live or current data.
- Extra payments are applied to principal every month from the first payment; the simulation walks the schedule month by month without rounding intermediate balances.
- Educational estimate only, not financial advice; confirm payment amounts and payoff dates with your loan servicer.
References
- Standard amortization formula — Monthly payment M = P x r / (1 - (1 + r)^-n) is the standard fixed-payment loan formula taught in finance and used by servicers for level-payment plans.
- Federal Student Aid repayment plans — Describes the 10-year Standard Repayment Plan and the income-driven plans this calculator does not simulate; federal rates are set annually and should be checked there.
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Last updated: September 4, 2026