Loan Amortization Journal Entry: Examples and Formula

A loan amortization journal entry records the split between interest expense and principal repayment for a payment period. This calculator works out a fixed-rate loan’s monthly payment and total interest from the loan amount, APR, and term; it does not create accounting entries or calculate the changing principal-and-interest split for each month.

Formula

The standard fixed-payment formula calculates a monthly payment that covers interest for the period and repays the balance over the stated number of months:

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

• P is the original principal, in dollars.
• r is the monthly interest rate as a decimal: APR ÷ 1,200. For an 8% APR, r = 0.08 ÷ 12.
• n is the number of monthly payments: loan term in years × 12.
• Total interest is the rounded monthly payment × n − P, in dollars.

The calculator rounds the payment to cents before calculating total interest. Actual loan documents may apply different day-count, payment, or rounding conventions.

Worked Example

Using the calculator’s default inputs: principal P = $20,000, APR = 8%, and term = 5 years.

1. Convert the APR to a monthly decimal rate: r = 8 ÷ 1,200 = 0.0066667.
2. Convert the term to monthly payments: n = 5 × 12 = 60.
3. Apply the formula: $20,000 × 0.0066667 ÷ [1 − (1.0066667)⁻⁶⁰] = $405.53 per month, rounded to cents.
4. Calculate total interest using the rounded payment: $405.53 × 60 − $20,000 = $4,331.80.

Assumptions

• The interest rate remains fixed for the full term.
• Payments are equal monthly amounts, made at the end of each period.
• Interest is compounded monthly at APR ÷ 12.
• Fees, taxes, insurance, PMI, and escrow are not included.

What a Loan Amortization Journal Entry Records

In bookkeeping, “loan amortization” commonly refers to recording each scheduled loan payment as it reduces the liability. The borrower generally recognizes interest expense for the period and reduces the loan payable by the principal portion. The lender’s records use corresponding accounts, but the entries shown here are from the borrower’s perspective.

For a payment of $405.53, suppose the lender’s amortization schedule shows $133.33 of interest and $272.20 of principal. The entry is:

• Debit Interest Expense: $133.33
• Debit Loan Payable: $272.20
• Credit Cash: $405.53

The debits equal the credit. Interest is an expense for the period; principal repayment reduces the amount owed and is not itself interest expense. The exact split should come from the lender’s schedule or statement, not from dividing the payment evenly.

How the Principal and Interest Split Changes

With a level-payment, fixed-rate loan, the payment may stay constant while its components change. Interest for a period is generally calculated on the outstanding balance, so the interest portion tends to fall as principal is repaid. The principal portion then tends to rise. For the example above, the first month’s interest under a simple monthly-rate calculation is $20,000 × 0.08 ÷ 12 = $133.33; the remaining $272.20 reduces principal to about $19,727.80.

For the next payment, interest is calculated on the new balance, subject to the lender’s calculation and rounding rules. A full amortization schedule repeats this process for each payment date. If payments are irregular, the rate changes, or the agreement uses a different interest method, the schedule may not match this simplified calculation.

Recording the Loan and Common Mistakes

When a borrower receives loan proceeds, a basic entry is a debit to Cash and a credit to Loan Payable for the amount received. Later payments are split between interest and principal as described above. The opening balance in the books should agree with the loan documents and any separately recorded costs or adjustments that apply to the entity’s accounting.

• Debiting the entire payment to interest: This overstates interest expense and leaves the loan liability too high.
• Crediting the entire payment to the liability: This omits the period’s interest expense.
• Using the original balance for every interest calculation: In a reducing-balance schedule, interest is based on the outstanding balance, not always the original amount.
• Ignoring dates and rounding: Payment timing and the lender’s rounding method can make small differences accumulate.
• Confusing loan amortization with asset amortization: A loan payment reduces a liability; amortizing an intangible asset allocates its cost as an expense over time. These are different accounting processes.

For a payment that crosses a reporting-period boundary, an organization may need to recognize interest incurred by the reporting date even if cash is paid later. The appropriate entry depends on the dates and the organization’s accounting policies; this calculator does not determine accruals or provide accounting or tax treatment.

Using the Estimate and Its Limits

Use the calculator to understand the approximate level payment implied by the stated principal, APR, and term. Compare its result with the payment and schedule supplied with the loan documents. If they differ, check whether the quoted amount includes fees or other charges, whether the rate is fixed, and whether payment frequency or timing differs from monthly end-of-period payments.

The displayed total interest assumes every scheduled payment is made on time and in the calculated amount for the full term. Extra payments, missed payments, variable rates, fees, and changes to the balance can alter the actual schedule. The calculator’s total uses its rounded monthly payment, so the final payment on a real loan may be adjusted to clear the remaining balance.

Frequently Asked Questions

What is the journal entry for a loan payment?
Debit Interest Expense for the period’s interest, debit Loan Payable for the principal repaid, and credit Cash for the total payment. Use the lender’s statement or amortization schedule for the split.

Is loan principal repayment an expense?
Principal repayment reduces the liability; it is not interest expense. Interest is recorded separately as an expense for the period, subject to the applicable accounting treatment.

How do I calculate interest for a monthly loan payment?
For a simple fixed-rate monthly schedule, multiply the outstanding balance by the monthly rate. A nominal APR divided by 12 gives the monthly decimal rate when the agreement uses monthly periodic interest.

Does this calculator give the journal entry for every month?
No. It estimates the level payment and total interest. To prepare each entry, use the period-specific interest and principal figures in the lender’s amortization schedule, then record the corresponding debit and credit amounts.

What is the difference between loan amortization and asset amortization?
Loan amortization describes repayment of a debt over time. Asset amortization allocates the cost of certain assets across periods. The terms are related, but they refer to different balances and journal entries.

This result is an estimate, and the lender’s disclosure gives the exact figures.

Related

• Revolving Term Loan Calculator: Payments and Interest
• Rupee Term Loan Calculator: Monthly EMI and Interest
• Repay Short-Term Loan? Calculate Payments and Interest

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