Student Loan Calculator

The Student Loan Calculator estimates what an education loan may cost once it enters repayment. Enter the balance, annual interest rate, and repayment term to see a standard fixed monthly payment, total interest, and total repaid. This is the broad student-loan planning page in the set: it helps you translate a college or graduate-school debt balance into a repayment commitment before you choose a term, accept a private refinance offer, or build a post-school budget.

This page is intentionally different from the student loan payment calculator, which is focused on the monthly payment and optional extra payments. Use this page when you want the overview: the balance entering repayment, the term in years, and the lifetime cost of a standard amortizing schedule. For federal plan comparisons, see the US student loan repayment calculator. For possible cancellation scenarios, use the student loan forgiveness calculator. For general cash-flow planning, connect the result to the budget calculator and debt-to-income calculator.

How to use this calculator

Start with the student loan balance you expect to repay. Do not automatically enter only the amount originally borrowed. If interest accrued while you were in school, during a grace period, or during deferment or forbearance, and that interest is capitalized, it becomes part of the balance. Private loans, federal unsubsidized loans, and graduate loans may behave differently, so use the number from your disclosure or servicer whenever possible.

Next, enter the annual interest rate. For one fixed-rate loan, use that loan’s stated annual rate. If you are estimating several loans together, use a weighted average rate rather than a simple average, because a high-rate loan with a large balance affects the payment more than a small loan with the same rate. Finally, enter the repayment term in years. The calculator converts years to months and rounds to the nearest whole month before computing the payment.

Formula used by the calculator

The calculator uses the standard amortization formula for a fixed monthly payment. First it converts the annual rate into a monthly rate:

$r = \frac{\text{annual interest rate}}{100 \times 12}$

It converts the repayment term into months:

$n = \text{rounded repayment years} \times 12$

For a positive interest rate, the monthly payment is:

$\text{monthly payment} = \frac{P \times r}{1 - (1 + r)^{-n}}$

Here P is the student loan balance, r is the monthly interest rate, and n is the number of monthly payments. Total paid and total interest are:

$\text{total paid} = \text{monthly payment} \times n$

$\text{total interest} = \text{total paid} - P$

When the annual interest rate is zero, the compute function skips the interest formula and divides the balance evenly across the rounded number of months:

$\text{monthly payment} = \frac{P}{n}$

Worked example matching the default inputs

Assume a student graduates with $30,000 entering repayment, a 5.5% annual interest rate, and a 10-year repayment term. The calculator rounds 10 years to 120 months. The monthly rate is 5.5 divided by 100 and then by 12, or about 0.0045833 per month.

Applying the formula gives an estimated monthly payment of $325.58. Over 120 payments, total repaid is $39,069.46. Total interest is the amount paid above the original repayment balance, so $39,069.46 minus $30,000 equals $9,069.46. The result note summarizes the same idea: $30,000 in student loans repaid over 10 years at 5.5% costs about $325.58 per month.

If the same balance were repaid over a longer term, the monthly payment would fall, but the balance would stay outstanding for more months. If the term were shorter, the payment would rise, but total interest would usually fall. That is the central tradeoff this calculator is meant to make visible.

Student loan context that affects the estimate

Student loan repayment is more complicated than a car loan or a standard personal loan because the repayment balance can change before regular billing starts. Subsidized federal loans may have different interest treatment during certain periods than unsubsidized or private loans. Interest may accrue during school, grace, deferment, or forbearance. If unpaid interest capitalizes, the future payment is calculated on a larger principal. That is why a careful balance entry matters more than the original borrowing total.

Federal student loans may also offer repayment plans that are not fixed-payment amortization. Income-driven plans can produce a payment below, equal to, or above the standard amount depending on income and family size. Private student loans usually rely more directly on the contract rate, term, and balance, but variable rates can change future payments. This calculator does not attempt to model those program-specific rules; it gives a clean baseline that is easy to compare.

Tips before choosing a repayment term

• Build the payment into a realistic first-year budget, including rent, taxes, insurance, transportation, food, emergency savings, and retirement contributions.
• Compare total interest, not only the first monthly payment. A smaller payment can be costly if it extends repayment for many years.
• If you plan to pay extra, confirm whether the servicer applies extra money to principal and whether you must give special instructions.
• If you have multiple loans, look at each rate. Paying extra toward the highest interest balance first can reduce total interest faster.
• Before refinancing federal loans into a private loan, consider federal protections such as income-driven plans, deferment options, and forgiveness eligibility that may be lost.

Sources

• Federal Student Aid, Types of loans — federal student loan categories and borrowing context.
• Federal Student Aid, Loan interest rate — explanation of student loan interest rates.
• Federal Student Aid, Repayment plans — overview of federal repayment-plan choices.
• CFPB, Student loans — consumer guidance for student loan borrowers.