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Guide

How mortgage payments are calculated

Your mortgage payment is usually two parts: principal and interest (P&I) plus escrow items like taxes and insurance. This guide shows the inputs that drive the payment so your estimates match what lenders use.

Mortgage payment calculator Amortization schedule What is PITI?

Mortgage payment inputs to verify

  • Loan amount, note rate, and term.
  • Taxes, insurance, HOA, and PMI assumptions.
  • Escrow rules or reserves used by the lender.
  • Time horizon if comparing scenarios.

The payment formula (high level)

  • Principal & interest: set by the loan amount, rate, and term.
  • Escrow items: property taxes and homeowners insurance (plus HOA and PMI when applicable).
  • Total payment: P&I + taxes + insurance + HOA + PMI.

Inputs you need

  • Home price and down payment (determines the loan amount).
  • Interest rate and term (15, 20, 30 years).
  • Annual property taxes and homeowners insurance.
  • Monthly HOA dues, if any.
  • PMI rate, if your down payment is below 20%.

Step-by-step workflow

  1. Calculate loan amount = home price minus down payment.
  2. Compute the monthly P&I payment from the rate and term.
  3. Convert annual taxes and insurance into monthly amounts.
  4. Add HOA and PMI if they apply.
  5. Compare the total to your lender estimate or Loan Estimate.

Why payments change over time

The P&I payment is fixed for fixed-rate loans, but escrow items can change after closing due to tax reassessments or insurance renewals. This is why total payment can rise even when the interest rate is fixed.

Common mistakes

  • Using APR instead of the note rate for P&I calculations.
  • Leaving out taxes or insurance when estimating affordability.
  • Ignoring HOA dues or PMI costs that affect the housing payment.
  • Comparing payments without matching the same term and rate.

Related tools

Related guides

FAQ

Does a bigger down payment always lower the total payment?

It lowers the loan amount and can remove PMI, which usually lowers the total. Taxes and insurance are based on the property, so those do not change with your down payment.

Why does my lender estimate differ from the calculator?

Lenders may use different tax or insurance assumptions and may include escrow reserves. Match their inputs to align results.

References

Next steps

Run the mortgage payment calculator Check DTI Mortgage payment topic

Educational use only. Not financial advice.

Last updated: 2026-02-17