Free calculator
Mortgage calculator
Estimate the monthly principal & interest on a home loan, plus the total interest and total you’ll pay over its full term. Enter the price and financing — the result is based on your own numbers.
The short answer
Last updated: July 2026
A mortgage’s monthly principal and interest comes from the amortization formula M = P·r·(1+r)ⁿ ÷ ((1+r)ⁿ − 1), where P is the loan amount, r the monthly rate, and n the number of payments. Total interest is that payment × number of payments minus the amount borrowed. This estimate excludes taxes, insurance, and PMI.
Primary references on this page:
After the estimate:
Self-management softwareMortgage calculator
Monthly payment, total interest, total paid.
Enter the price and your financing to estimate the monthly principal & interest — plus what the loan really costs over its full term.
Home price
$
Down payment
20%
0%
100%
$80,000 down, financing $320,000.
Interest rate (APR)
6.50%
0%
12%
Loan term
30 yrs
5 yrs
40 yrs
Input-driven result
Your inputs
Formula
Result below
Monthly principal & interest
$2,023
$320,000 loan at 6.50% over 30 years.
Total interest over the loan
$408,142
What you pay the lender on top of the $320,000 borrowed.
Total paid over the loan
$728,142
$2,023/mo × 360 payments — principal plus interest.
Loan cost composition
Principal borrowed
$320,000
Interest over term
$408,142
Total paid
$728,142
Estimate based on your inputs. Not a promise of results.
Estimate only. This is principal & interest — it excludes property taxes, homeowners insurance, HOA dues, and mortgage insurance (PMI), which raise your actual monthly payment.
How it works
How this tool works.
A mortgage payment is more than a monthly number — it’s a decades-long commitment where the interest can rival the price of the home itself. Seeing the monthly payment and the lifetime cost side by side makes the trade-offs concrete before you sign.
Enter the home price, your down payment, the interest rate, and the term, and this calculator estimates the monthly principal & interest along with the total interest and total paid over the life of the loan. It’s arithmetic on the figures you provide — an illustration, not a loan offer or a rate quote.
Make the result useful
Mortgage payment decisions
Loan amount is the principal actually financed, not the purchase price.
Interest rate is the note rate for the modeled loan; compare the same term when testing rates.
Loan term is the amortization length in years; taxes, insurance, HOA, and utilities remain separate owner costs.
Use the payment result inside a full property budget before treating it as affordability or cash flow.
Calculation lens
principal-and-interest payment from loan amount, rate, and term
Use the output as a documented scenario result, not a guarantee.
The output excludes taxes, insurance, escrow, fees, and future rate changes.
Questions landlords ask
Questions about this tool and its limits.
Built by a landlord who's done every one of these jobs by hand.
Aptoria was built by an owner-operator managing a Brooklyn portfolio — the 11pm calls, the awkward rent texts, the April receipt-pile — not by a software team guessing at the problem.
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