Student Loan Amortization Table Calculator

This student loan amortization table calculator estimates the fixed monthly payment and total interest for a loan, then the figures can be used to build a month-by-month repayment schedule. Enter the loan amount, annual APR, and term; the calculator returns the payment and total interest under a standard fixed-rate repayment formula.

Formula

The calculator uses the standard level-payment formula for a loan with a fixed annual percentage rate and monthly payments:

Monthly payment = P × r ÷ [1 − (1 + r)⁻ⁿ]

Total interest = (monthly payment × n) − P

• P is the starting loan principal, in dollars.
• r is the monthly interest rate, calculated as APR ÷ 1,200. For example, 8% APR gives a monthly rate of 0.08 ÷ 12, or about 0.006667.
• n is the number of monthly payments, calculated as years × 12.

The formula assumes each payment is the same and occurs monthly. The calculator displays the payment to the nearest cent, and its total-interest result uses that displayed, rounded payment multiplied by the number of scheduled payments. A real servicer’s payment allocation and final amount can differ by a small amount because of rounding and account-specific timing.

Worked Example

Using the defaults—$20,000 principal, 8% APR, and a five-year term—the schedule has 5 × 12 = 60 monthly payments. The monthly rate is 8 ÷ 1,200 = 0.0066667.

Monthly payment = 20,000 × 0.0066667 ÷ [1 − (1 + 0.0066667)⁻⁶⁰] = $405.53 when rounded to cents.

Total of scheduled payments = $405.53 × 60 = $24,331.80. Estimated total interest = $24,331.80 − $20,000 = $4,331.80.

Assumptions

• The interest rate stays fixed for the full term.
• Payments are made monthly, at regular intervals, with the first payment one month after the loan begins.
• Interest is modelled monthly at APR ÷ 12, without daily-accrual adjustments.
• Fees, taxes, insurance, payment pauses, late charges, discounts, and extra payments are not included.

How to Read an Amortization Table

An amortization table breaks a repayment plan into individual payment periods. A useful full table typically shows the payment number or date, payment amount, interest charged for that period, principal repaid, and remaining balance. The calculator above gives the scheduled payment and total interest; it does not display every monthly row, so a complete table requires applying the monthly calculations repeatedly.

For a basic fixed-rate schedule, each period’s interest is the opening balance multiplied by the monthly rate. The principal portion is the payment minus that interest. Subtract the principal portion from the opening balance to find the closing balance, which becomes the next period’s opening balance.

1. Start with the original principal as the first opening balance.
2. Calculate that month’s interest from the opening balance and monthly rate.
3. Subtract the interest from the scheduled payment to find principal repaid.
4. Subtract principal repaid from the opening balance to get the new balance.
5. Repeat for each payment period, allowing for final-payment adjustments if needed.

In the example’s first month, estimated interest is $20,000 × 0.0066667, or about $133.33. Of the $405.53 payment, about $272.20 therefore reduces principal, leaving an estimated balance of $19,727.80. Later interest charges generally decline as the balance falls, while more of each level payment goes toward principal.

When a Student Loan Table Is Useful

A table can make the mechanics of repayment easier to see than a single payment quote. It helps illustrate the relationship between principal, rate, term, and interest over time. For example, with the same principal and rate, extending the term lowers the calculated scheduled payment but generally increases the number of periods over which interest is charged. Shortening the term generally raises the scheduled payment while reducing the time the balance accrues interest.

Use figures that match the loan being modelled. If multiple loans have different balances, rates, or repayment terms, calculate each separately rather than treating them as one loan at an averaged rate. For an estimate of a combined payment, the individual scheduled payments can be added, but that total does not replace each loan’s separate balance and interest schedule.

Common Limits and Misconceptions

An amortization estimate is not a payoff quote. Student-loan interest may be calculated using account-specific methods, and payment dates, unpaid accrued interest, fees, capitalization, or a variable rate can change the actual schedule. Get the current payoff amount and payment details from the loan servicer when exact account figures are needed.

• APR is not the monthly rate. Divide an annual percentage rate by 12 to get a monthly decimal rate; with APR entered as a percentage, the calculator uses APR ÷ 1,200.
• A payment is not all principal. The interest portion is paid first in the simplified schedule; only the remainder reduces principal.
• Extra payments change the schedule. If extra money is applied to principal, the balance and future interest can fall faster, but the result depends on how the servicer applies that payment.
• Variable rates cannot be represented by one fixed APR. A schedule using one APR is only a fixed-rate illustration if the actual rate changes.

This calculator models general loan arithmetic only. It does not model student-loan repayment programs, eligibility, forgiveness, or other account-specific arrangements; check the applicable program information and servicer records for those details. Obtain the actual APR, term, fees, and payment schedule from the lender or servicer rather than treating the example defaults as a quote.

Frequently Asked Questions

What is an amortization table for a student loan?
An amortization table lists each scheduled payment and shows how much is estimated to go to interest and principal, along with the remaining balance after payment.

How do I calculate a student loan monthly payment?
Use the principal, monthly rate (APR ÷ 12), and number of monthly payments in the fixed-payment formula shown above. APR must be converted from a percentage to a decimal rate for the formula.

Why does the interest part of a payment change?
In a standard fixed-rate schedule, interest is calculated on the remaining balance. As principal is repaid and the balance falls, the interest portion usually declines, leaving more of a level payment for principal.

Does this calculator include extra payments?
No. It estimates regular level payments over the stated term. Extra payments can change the payoff timing and interest, and their effect depends on how they are credited to the account.

Can I use this table for a variable-rate student loan?
Only as a snapshot using one assumed APR. If the rate changes, the actual payment allocation and remaining balance may differ from the fixed-rate illustration.

The result is an estimate; the lender’s disclosure gives the exact figures.

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in p | Loan amount | $ | 20000 | 1 | 100000000
in apr | Interest rate (APR) | % | 8 | 0.01 | 100
in yrs | Loan term | years | 5 | 0.0833 | 50
out pmt | Monthly payment | $ | p * (apr / 1200) / (1 - (1 + apr / 1200) ^ -(yrs * 12)) | 2
out int | Total interest | $ | pmt * yrs * 12 - p | 2