Student Loan Calculator
A student loan calculator applies M = P × r(1 + r)ⁿ ÷ ((1 + r)ⁿ − 1) to each loan, where r is the yearly rate ÷ 12 and n is the number of months. Three example loans totaling $25,000 at 5.5%, 6.53% and 7.05%, with a 6-month grace period, cost $292.18 a month on the 10-year Standard plan, including $10,059.53 in interest.
Your loans one by one
| Loan | Rate | Owed at start | Payment | Interest in repayment | Paid off |
|---|---|---|---|---|---|
| Loan A | 5.5% | $5,500.00 | $59.69 | $1,662.67 | Apr 2037 |
| Loan B | 6.53% | $7,744.88 | $88.02 | $2,816.34 | Apr 2037 |
| Loan C | 7.05% | $12,423.00 | $144.47 | $4,912.64 | Apr 2037 |
Compare repayment plans
| Plan | Monthly | Total interest | Total paid | Payoff |
|---|---|---|---|---|
| Standard 10-year | $292.18 | $10,059.53 | $35,059.53 | Apr 2037 |
| Consolidation, 20 years | $193.27 | $21,383.19 | $46,383.19 | Apr 2047 |
Year-by-year schedule
| Year | Ends | Paid | Interest | Balance |
|---|---|---|---|---|
| 1 | Apr 2028 | $3,506.16 | $1,615.17 | $23,776.89 |
| 2 | Apr 2029 | $3,506.16 | $1,500.86 | $21,771.59 |
| 3 | Apr 2030 | $3,506.16 | $1,365.52 | $19,630.95 |
| 4 | Apr 2031 | $3,506.16 | $1,221.00 | $17,345.79 |
| 5 | Apr 2032 | $3,506.16 | $1,066.56 | $14,906.19 |
| 6 | Apr 2033 | $3,506.16 | $901.68 | $12,301.71 |
| 7 | Apr 2034 | $3,506.16 | $725.53 | $9,521.08 |
| 8 | Apr 2035 | $3,506.16 | $537.39 | $6,552.31 |
| 9 | Apr 2036 | $3,506.16 | $336.35 | $3,382.50 |
| 10 | Apr 2037 | $3,504.09 | $121.59 | $0.00 |
Show steps
- Interest before repayment uses the daily interest formula: balance × (rate ÷ 365.25) × days. Over 6 months that is the same as balance × rate × 6 ÷ 12. Subsidized loans build up none. Total: $667.88.
- Amount owed when repayment starts: $25,000.00 + $667.88 = $25,667.88. The interest stays separate from principal, so it does not earn interest itself.
- Weighted average rate = (sum of balance × rate) ÷ total balance = ($5,500.00 × 5.5% + $7,744.88 × 6.53% + $12,423.00 × 7.05%) ÷ $25,667.88 ≈ 6.561%. A Direct Consolidation Loan rounds this up to the nearest one-eighth of 1%: 6.625%.
- Each loan gets its own fixed payment over n = 10 × 12 = 120 months. For Loan A: M = P × r(1 + r)ⁿ ÷ ((1 + r)ⁿ − 1) with P = $5,500.00, r = 5.5% ÷ 12 ≈ 0.0045833: (1 + r)ⁿ ≈ 1.7311, so M ≈ $59.69.
- The other payments work the same way: Loan B $88.02, Loan C $144.47. Add them up: $292.18 a month.
- Each month, interest is the principal × rate ÷ 12, rounded to the cent. The payment covers unpaid interest first, then principal.
- Totals: 120 months of payments add up to $35,059.53. That is $25,000.00 borrowed + $10,059.53 interest ($667.88 before repayment and $9,391.65 during it). Last payment: Apr 2037.
How to use the student loan calculator
- Enter each loan’s balance, interest rate and type (subsidized or unsubsidized). You can find them on StudentAid.gov or your servicer’s website. Add up to 8 loans.
- Enter how many months remain before your first payment and what happens during that time: school or grace, deferment, or forbearance. Use 0 if you are already repaying.
- Choose a plan: Standard (10 years), Extended (25 years, if you owe more than $30,000), Direct Consolidation, or a custom term.
- Add an extra monthly payment to see how much interest you save and when you will be debt-free.
The calculator does not model income-driven plans such as IBR or the new Repayment Assistance Plan. For those, use the official Repayment Calculator on StudentAid.gov, which uses your income and family size.
Student loan payment formula
On the Standard plan, StudentAid.gov says your payment is a fixed amount, at least $50 a month, set so the whole loan and its interest are paid off within 10 years. That fixed payment comes from the amortization formula:
M = P × r(1 + r)ⁿ ÷ ((1 + r)ⁿ − 1)
- P is the amount you owe when repayment starts.
- r is the monthly rate: the yearly rate as a decimal ÷ 12.
- n is the number of payments: 120 for 10 years.
Example: a $12,000 loan at 7.05% has r = 0.0705 ÷ 12 = 0.005875 and (1.005875)¹²⁰ ≈ 2.0197, so M = 12,000 × 0.005875 × 2.0197 ÷ 1.0197 ≈ $139.64 a month. With several loans, each loan gets its own payment, and your bill is the sum.
Interest before repayment and capitalization
Federal Direct Loans are daily-interest loans. StudentAid.gov gives the formula as principal × (rate ÷ 365.25) × days since your last payment. Over a few months, that works out to about balance × rate × months ÷ 12.
- Subsidized loans build up no interest while you are in school, in the grace period or in deferment.
- Unsubsidized and PLUS loans build up interest the whole time.
- During forbearance, every loan builds up interest.
In the example, the $7,500 unsubsidized loan at 6.53% gathers 7,500 × 0.0653 × 6 ÷ 12 ≈ $244.88 over a 6-month grace period, and the $12,000 loan at 7.05% gathers $423.00. Together that is $667.88 before the first payment.
Capitalization means unpaid interest is added to principal, so you then pay interest on interest. For Direct Loans held by the Department of Education, StudentAid.gov lists two times this happens: after a deferment on an unsubsidized loan, and when you leave the IBR plan or no longer qualify for an income-based payment. Interest from school, the grace period or forbearance stays separate on these loans. Older FFEL loans held by private lenders can capitalize at more points.
The difference is small on a 10-year plan. If the $667.88 in the example came from a deferment and capitalized, the payment would be $292.31 instead of $292.18, and total interest $10,077.32 instead of $10,059.53. Paying the interest as it builds up, about $111.31 a month, saves more: $239.40 over the life of the loans.
Weighted average rate and Direct Consolidation
According to StudentAid.gov, a Direct Consolidation Loan has a fixed rate equal to the weighted average of the rates on the loans you consolidate, rounded up to the nearest one-eighth of 1%. To find a weighted average, multiply each balance by its rate, add the results and divide by the total balance.
For the example loans when repayment starts: (5,500 × 5.5 + 7,744.88 × 6.53 + 12,423 × 7.05) ÷ 25,667.88 ≈ 6.561%. Eighths of a percent run 6.5%, 6.625%, 6.75%, so the consolidation rate rounds up to 6.625%. Any interest you have not paid becomes part of the new principal.
The term on a consolidation loan depends on how much you owe. Under the Standard plan, StudentAid.gov allows:
| Student loan debt | Longest Standard term |
|---|---|
| Less than $7,500 | 10 years |
| $7,500 to $9,999 | 12 years |
| $10,000 to $19,999 | 15 years |
| $20,000 to $39,999 | 20 years |
| $40,000 to $59,999 | 25 years |
| $60,000 or more | 30 years |
Consolidating the example ($25,667.88 over 20 years at 6.625%) lowers the payment to $193.27, $98.91 less a month. Total interest, though, rises to $21,383.19, which is $11,323.66 more. StudentAid.gov warns about exactly this trade-off: a longer repayment period means more payments and more interest.
Federal repayment plans after July 1, 2026
The One Big Beautiful Bill Act changed the repayment options. What you can choose now depends on when your loans were first disbursed:
- Standard: fixed payments for up to 10 years (10 to 30 years for consolidation loans). New Direct Loans disbursed on or after July 1, 2026 use the Tiered Standard Plan instead, which lasts 10 to 25 years depending on how much you borrowed. Use the Custom option for that term.
- Graduated: payments start low and rise every two years, are never less than the interest that accrues, and are never more than three times any other payment. This plan is not available for Direct Loans disbursed on or after July 1, 2026. StudentAid.gov does not publish the exact step formula, so we do not estimate it.
- Extended: fixed or graduated payments for up to 25 years if you have more than $30,000 in Direct Loans (or in FFEL loans). It is also closed to new Direct Loans disbursed on or after July 1, 2026.
- Income-driven plans: IBR and the new Repayment Assistance Plan (RAP) base payments on income. Check these in the official Repayment Calculator.
How extra payments shorten student loans
Extra money goes to principal, so later months charge interest on a smaller balance. The calculator sends extra payments to the highest-rate loan first; ask your servicer to apply them the same way. On the example, $50 more a month saves $1,881.59 in interest and ends repayment 7 months early. $250 more a month saves $5,203.61 and ends it 4 years and 7 months early.
Common student loan calculation mistakes
- Using the yearly rate as r. Divide by 12. Using 0.0705 instead of 0.005875 gives a payment many times too large.
- Averaging rates without weights. A plain average of 5.5%, 6.53% and 7.05% is 6.36%, but the larger loans carry higher rates, so the weighted average is higher.
- Rounding the consolidation rate to the nearest eighth. It always rounds up, so 6.561% becomes 6.625%, not 6.5%.
- Forgetting interest before repayment. Unsubsidized loans grow during school and grace even when you make no payments.
- Judging a plan by its payment alone. A lower payment over more years usually means more interest.
This calculator gives estimates for planning and learning, not financial advice. Your servicer sets your actual payment.
Sources
- Federal Student Aid: Repayment Plans
- Federal Student Aid: Standard Repayment Plan
- Federal Student Aid: Graduated Repayment Plan
- Federal Student Aid: Extended Repayment Plan
- Federal Student Aid: Consolidating Student Loans
- Federal Student Aid: Interest Rates and Fees (how interest is calculated and when it capitalizes)
- Federal Student Aid: Student Loan Repayment (prepayments)
- Federal Student Aid: One Big Beautiful Bill Act updates
Sources checked November 2026.
Student loan repayment practice quiz: 10 questions
Test yourself with 10 multiple-choice questions. Choose an answer and press Submit to see if you are right and why. Your score appears at the end.
Multiply each balance by its rate and divide by the total: (4,000 × 5 + 6,000 × 7) ÷ 10,000 = 62,000 ÷ 10,000 = 6.2%. A plain average (6%) ignores that more money is at 7%.
The rate is rounded up to the nearest one-eighth of 1%. The eighths near 6.209% are 6.125% and 6.25%, and rounding up gives 6.25%.
Interest ≈ balance × rate × months ÷ 12 = 8,000 × 0.06 × 6 ÷ 12 = $240. $480 is a full year of interest.
Interest does not build up on subsidized loans while you are in school, in the grace period or in deferment.
With r = 0.005 and n = 120, (1.005)¹²⁰ ≈ 1.8194 and M = 10,000 × 0.005 × 1.8194 ÷ 0.8194 ≈ $111.02. $83.33 ignores interest (10,000 ÷ 120).
The Standard Plan payment is at least $50 a month, so the payment rises to $50 and the loan is paid off before 10 years.
For Direct Loans held by the Department of Education, unpaid interest capitalizes after a deferment on an unsubsidized loan, or when you leave the IBR plan.
StudentAid.gov's table gives up to 20 years for $20,000 to $39,999 of student loan debt.
Monthly interest ≈ balance × rate ÷ 12 = 12,000 × 0.07 ÷ 12 = $70.00. $840 is a whole year.
Quiz complete
Frequently asked questions
How is a student loan payment calculated?
For a fixed-payment plan, use M = P × r(1 + r)ⁿ ÷ ((1 + r)ⁿ − 1), with r equal to the yearly rate ÷ 12 and n equal to the number of months. Work out each loan separately and add the payments together. On the Standard plan the payment is at least $50 a month.
What is the monthly payment on $30,000 in student loans?
Over 10 years at an example rate of 6.53%, a $30,000 loan costs $341.10 a month, with $10,932.37 in total interest. A $10,000 loan at the same rate costs $113.70 a month. Your own payment depends on your rates and plan.
Does student loan interest capitalize after the grace period?
Not on Direct Loans held by the Department of Education. StudentAid.gov lists capitalization after a deferment on an unsubsidized loan and when you leave IBR. FFEL loans held by private lenders may still capitalize after the grace period.
How is the interest rate on a consolidation loan calculated?
Take the weighted average of your loans' rates, weighted by balance, and round it up to the nearest one-eighth of 1%. Loans of $10,000 at 5% and $10,000 at 5.25% average exactly 5.125%, which is already an eighth, so the rate stays 5.125%.
Is it better to pay extra on student loans?
Extra payments cut interest and shorten repayment, especially on high-rate loans. StudentAid.gov notes that you can prepay even while you are in school or in the grace period. Prepayments do not count as qualifying payments for forgiveness programs, so if you are working toward forgiveness, check that first.
Related calculators
Related to This Article
More math articles
- Free Printable Grade 5 Math for Vermont SBAC Students: 49 Single-Skill PDF Worksheets
- Structural Reform: The Sixteenth and Seventeenth Amendments
- Why Prejudice and Conflict Develop
- What Makes 10 (and 100)? — Fast Number-Bond Game
- Top 10 5th Grade STAAR Math Practice Questions
- Civil disobedience
- Cross-Cutting and Reinforcing Political Cleavages
- Nonresponse bias
- The Best Grade 3 ELA Practice Tests for Indiana Students
- PSAT/NMSQT Math Flashcards (Free Online: Formulas, Terms & Concepts)
What people say about "Student Loan Calculator: Multiple Loans & Payoff Date"?
No one replied yet.