Mortgage Calculator
A mortgage payment estimate needs four inputs: the loan amount, the annual interest rate, the term in years, and the recurring costs bundled into the payment. Fair Calcs keeps those assumptions visible so you can change any of them.
Mortgage payment estimate
How the estimate works
- Monthly rate equals the annual rate divided by 12.
- Number of payments equals the term in years multiplied by 12.
- Principal and interest equal the loan amount times the monthly rate, divided by one minus (one plus the monthly rate) raised to the negative number of payments.
- Total interest equals the sum of every payment minus the original loan amount.
What an estimate cannot tell you
Property taxes, homeowners insurance, mortgage insurance, HOA dues, escrow shortages, rate locks, points, and closing costs vary by lender, property, and location. Results are estimates only and are not lending, tax, legal, or financial advice.
Assumptions and review
Formula review: July 29, 2026. Uses standard fixed-rate monthly amortization and only the editable values shown above.
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Frequently asked questions
How is a mortgage payment calculated?
Principal and interest are calculated from the loan amount, the periodic interest rate, and the number of payments using the standard amortizing loan formula. Each payment covers the interest accrued that month first, and the remainder reduces the balance.
What is included in a monthly mortgage payment (PITI)?
PITI stands for principal, interest, taxes, and insurance. Many payments also include mortgage insurance and homeowners association dues, so the amount leaving your account is usually larger than the principal-and-interest figure alone.
What is amortization?
Amortization is the schedule that shows how each payment splits between interest and principal over the life of the loan. Early payments are mostly interest, and later payments are mostly principal, which is why extra early payments save the most interest.