Finance · Mortgage
Mortgage Payment
Monthly P&I, full payment estimate, and amortization summary for homeowners.
Last reviewed: February 18, 2026
Guided Flow
Next steps
Finance
Check affordability
Turn your monthly payment into a realistic max home price.
Finance
Estimate closing costs
Model buyer cash-to-close and seller-side estimates before making an offer.
Finance
Estimate PMI drop-off
See when PMI may end and how much it may cost before then.
Guide
Read: payment breakdown
Understand what drives principal, interest, tax, and insurance totals.
What this calculator does
Monthly P&I, full payment estimate, and amortization summary for homeowners.
How it's calculated
- Inputs are validated before running the calculator-specific compute() function.
- Core math is deterministic and implemented in src/lib/calculators/mortgage-payment.ts.
- Results are recalculated instantly as values change and are shareable via query parameters.
- Disclosure assumptions and limitations are shown on-page for decision context.
Example
Example scenario: Loan amount = 420000 USD; Interest rate = 6.5 %; Loan term = 30 years; Annual property tax = 6200 USD. Sample output: Monthly principal & interest: $2,654.69
Common mistakes
- Using optimistic rates or appreciation assumptions without testing a conservative case.
- Ignoring taxes, insurance, HOA, or maintenance in monthly cost planning.
- Treating modeled outputs as guaranteed quotes rather than planning estimates.
- Not comparing at least two scenarios before making a financing decision.
- Skipping professional review for legal, tax, underwriting, or insurance details.
FAQs
Does this include PMI?
Not by default. If you expect PMI, add it to HOA or include it as an extra monthly cost in your own budget.
Why is year-one interest larger than principal?
With fixed-rate mortgages, interest is calculated on the remaining balance, which is highest early in the loan.
Can I use this for a 15-year mortgage?
Yes. Change the term to 15 years to compare payment and interest against a longer term.
Can taxes and insurance stay flat over time?
No. This tool assumes constant annual values, but real escrow costs can change over time.
Is this exact lender payoff math?
It follows standard amortization math, but lender-specific timing and rounding can produce small differences.