Home Loan Calculator With Amortization Table

A home loan calculator with an amortization table estimates your monthly principal-and-interest payment and shows how each scheduled payment is divided between interest and principal. Enter the loan amount, annual APR, and term to see the payment and total interest; the table itself is a month-by-month schedule that a lender’s detailed quote may extend with escrow or other charges.

Formula

For a fixed-rate loan with equal monthly payments, the scheduled payment is calculated with the standard level-payment formula:

Payment = P × r ÷ [1 − (1 + r)⁻ⁿ]

• P is the amount borrowed, in dollars.
• r is the monthly interest rate, calculated as annual APR ÷ 1,200. For an 8% APR, r = 0.08 ÷ 12, or about 0.006667 per month.
• n is the number of monthly payments, calculated as loan term in years × 12.

The payment is rounded to the nearest cent. Total interest in this calculator is rounded monthly payment × number of payments − original loan amount. The amortization schedule uses the same basic monthly bookkeeping: interest for a month is the opening balance multiplied by the monthly rate, and principal repaid is the payment minus that interest. The next balance is the opening balance minus principal repaid.

Worked Example

Using the calculator’s default values—$20,000 principal, 8% APR, and a 5-year term—there are 5 × 12 = 60 monthly payments. The monthly rate is 8 ÷ 1,200 = 0.0066667.

Payment = 20,000 × 0.0066667 ÷ [1 − (1.0066667)⁻⁶⁰] ≈ $405.53 per month, rounded to cents. Using that rounded payment, total payments are $405.53 × 60 = $24,331.80. Estimated total interest is $24,331.80 − $20,000 = $4,331.80.

The first month’s interest is approximately $20,000 × 0.0066667 = $133.33. About $405.53 − $133.33 = $272.20 of the first payment reduces principal, leaving a balance of approximately $19,727.80. Later interest charges are smaller as the balance falls. The final scheduled payment may differ slightly in a real account because of payment dates, rounding, or lender adjustments.

Assumptions

• The interest rate stays fixed throughout the stated term.
• Payments are equal, made monthly, and applied at the end of each monthly period.
• Interest accrues monthly using APR divided by 12; the calculator uses the standard fixed-payment formula.
• The estimate excludes fees, taxes, homeowners insurance, mortgage insurance, escrow, and any other charges not entered as inputs.

How to Read an Amortization Table

A full amortization table typically has one row per payment period. Useful columns include the payment number or date, opening balance, scheduled payment, interest, principal, and closing balance. To build each row, calculate interest on the opening balance, subtract that interest from the payment to find principal repaid, then subtract principal from the opening balance.

For example, if a row begins with a $19,727.80 balance at the example’s monthly rate, interest is about $131.52. With a $405.53 payment, roughly $274.01 goes to principal, and the new balance is about $19,453.79. Values are approximate because each row is rounded here. A lender’s ledger may retain more precision internally and adjust the last payment to clear the balance.

Early in a fully amortizing loan, interest generally forms a larger share of each level payment because the outstanding principal is larger. As principal is repaid, the interest portion declines and the principal portion grows. This is not a separate interest penalty at the start: it follows from calculating interest on the remaining balance each period.

What the Calculator Includes—and Excludes

The calculator estimates principal and interest only. A housing payment can also include property taxes, homeowners insurance, mortgage insurance, association charges, or escrow collections, depending on the loan and arrangement. Those expenses do not reduce the principal balance in this formula, so they should not be mistaken for amortization.

APR is entered as a yearly percentage and converted to a monthly rate by dividing by 12. The calculation treats that APR as the periodic-rate input for a fixed-rate payment formula; it does not model every way fees or other APR components may be disclosed. For a variable-rate loan, future payments can change as the rate changes, so a single fixed-rate schedule cannot predict the full repayment path.

Using the Estimate Carefully

• Enter the amount actually financed, not automatically the property’s purchase price. A down payment or financed costs can make those figures different.
• Use the annual percentage rate and loan term from the figures you are examining. Rates and charges are inputs, not predictions; obtain applicable figures from the lender.
• Check that the term is entered in years. The formula converts years to months; entering months as years would greatly overstate the number of payments.
• Use the schedule to understand the timing of principal and interest, not as a statement of taxes, insurance, cash due at closing, or loan approval.

Rounding matters when a schedule is reproduced by hand: rounding each row to cents can create small differences in the ending balance. A spreadsheet or lender statement may use greater precision and apply a slightly different final payment. Extra payments are also not represented by this basic calculator; estimating them requires specifying their amounts, dates, and how they are applied.

Frequently Asked Questions

Does a home loan payment include property taxes and insurance?
No. This calculator’s payment is principal and interest only. Taxes, insurance, mortgage insurance, and escrow amounts are not included unless separately estimated outside the formula.

Why does the interest portion decrease over time?
Interest is calculated on the remaining principal. As scheduled payments reduce that balance, the next period’s interest is generally lower, leaving more of the same payment to reduce principal.

Can I get an amortization table from these results?
Yes. Start with the loan amount, calculate monthly interest as opening balance × APR ÷ 1,200, subtract interest from the monthly payment to find principal, and subtract that principal from the balance. Repeat for each month; a full calculator table would display those values in separate rows.

Does a shorter loan term always mean less interest?
For the same principal and fixed APR, a shorter fully amortizing term has fewer payment periods and generally less total interest, but its scheduled monthly principal-and-interest payment is higher. This calculation does not assess affordability or other costs.

Is APR the same as the interest rate?
Not necessarily. APR is a yearly borrowing-cost measure that may account for certain charges, while a loan’s stated interest rate is the rate used to accrue interest. This calculator uses the APR input as its rate for a simplified estimate, so compare its assumptions with the lender’s disclosure.

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

Related

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• Vehicle Loan Amortization Table Calculator
• Amortization Table Formula: Calculate Each Payment

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 | $ | round(p * (apr / 1200) / (1 - (1 + apr / 1200) ^ -(yrs * 12)), 2) | 2
out int | Total interest | $ | pmt * yrs * 12 - p | 2