Mortgage Calculator USA - Monthly Payment & Affordability
Mortgage Calculator - Monthly Payment & Affordability
Estimate monthly payment and cash to close with taxes, insurance, PMI and HOA. For home buyers.
What Is a Mortgage Calculator and Why You Need One?
A mortgage calculator helps you estimate monthly cost of buying or refinancing a home. A real monthly housing estimate may include principal and interest, property taxes, homeowners insurance, mortgage insurance when applicable, and HOA dues.
This mortgage calculator combines all those costs. You enter your numbers, we show estimated monthly housing payment. You can compare $500k vs $600k, different down payments, different rates, different taxes. This is educational estimate. It does not determine if you qualify, does not guarantee approval, does not provide rate quote, and does not calculate exact cash to close.
How This Mortgage Calculator Works
Calculator uses standard fixed-rate mortgage amortization formula to estimate principal and interest. Then adds monthly amounts you enter for property taxes, homeowners insurance, HOA dues, and estimated PMI when applicable. All in your browser.
This calculator estimates: principal and interest, property taxes, homeowners insurance, estimated PMI when down payment below 20%, HOA dues, estimated monthly housing cost, and estimated cash-to-close based on 2.9% closing-cost assumption.
Mortgage Payment Formula
Principal-and-interest uses standard amortization formula:
M = P [r(1+r)n] / [(1+r)n - 1]
P is loan amount. r is monthly interest rate (annual/12/100). n is total number of monthly payments (30-year = 360).
Monthly housing = Principal & Interest + Property Tax/12 + Insurance/12 + HOA + Estimated PMI. If 0% interest, loan amount divided by number of payments.
Real Example: $600,000 Home
Example with $600,000 home price, 20% down $120,000, $480,000 loan, 6.75% rate, 30-year fixed, $6,000 annual taxes, $1,800 insurance, no HOA, no PMI (20% down).
- Estimated Principal & Interest: ~$3,113.27 / month
- Property Taxes: $500 / month
- Homeowners Insurance: $150 / month
- Estimated Total: ~$3,763.27 / month
Total interest over 30 years approximately $640,778 if loan remains full term. Example only.
Conforming Loan Limits
National baseline conforming loan limit for one-unit property is $832,750 in most of the U.S. Higher limits apply in designated high-cost areas. County-specific limits should be checked. A mortgage above applicable conforming limit may be considered jumbo loan. Applicable limit depends on location and property type. For example above, $480,000 loan is below $832,750 baseline, likely conforming, but verify county limit.
What Affects Your Monthly Payment? 5 Key Factors
1. Down Payment and LTV Ratio
Down payment affects amount borrowed and LTV ratio. Lower down generally means higher loan balance and may result in mortgage insurance for some loan programs.
2. Interest Rate
Mortgage rate can have substantial effect on monthly P&I payment. Rates vary by market conditions, loan type, credit profile, LTV, property characteristics, lender pricing.
3. Property Taxes
Property taxes vary by state, county, municipality, assessed value, exemptions, local tax rules. Use actual or verified tax information.
4. Loan Term
Longer term generally produces lower monthly P&I but may result in more total interest. Shorter term may reduce total interest.
5. Insurance and HOA
Insurance premiums and HOA dues vary by property and location. Obtain property-specific figures.
How PMI Works
Private mortgage insurance commonly associated with certain conventional mortgages when down payment results in high LTV - typically below 20% down. Requirements vary by loan type, lender, insurer, LTV, credit characteristics.
This calculator uses PMI rate you enter to produce simplified estimated monthly PMI amount when down payment below 20%. Default 0.75% is example and not a quote.
FHA, VA, and Conventional Loans
FHA Loans: FHA-insured mortgages have mortgage-insurance requirements that differ from conventional PMI. May have upfront and ongoing costs. Check current federal housing guidance.
VA Loans: VA-backed mortgages generally do not require monthly private mortgage insurance. Eligible borrowers may be responsible for funding fee unless exemption applies. Check current federal veteran housing guidance.
Conventional Loans: Requirements vary by lender and loan program. PMI may apply in certain circumstances.
How Much House Can You Afford? 28/36 Guideline
Commonly referenced 28/36 rule is traditional budgeting guideline, not universal approval requirement. Lenders use different underwriting standards. Traditional guideline often described as approximately 28% of gross monthly income for housing and 36% for housing plus other recurring debts.
This calculator's housing-ratio compares estimated monthly housing payment with gross monthly income. Does not calculate complete back-end DTI because it does not collect all recurring monthly debt payments.
Important Limitations
This calculator provides estimates for educational and budgeting purposes. Not a mortgage offer, approval, underwriting decision, rate quote, or Closing Disclosure. Rates, taxes, insurance, PMI, HOA, fees can change. Does not determine eligibility for conventional, FHA, VA, USDA, jumbo programs. 28/36 percentages are budgeting guidelines. PMI simplified. Conforming loan limits vary by county - baseline $832,750. Always verify with applicable lender, servicer, or professional.
Frequently Asked Questions
How accurate is a mortgage calculator?
Can provide useful mathematical estimate when inputs accurate, but cannot reproduce every cost or underwriting factor. Lender's Loan Estimate should be used for final figures.
What is included?
Estimates principal and interest, property taxes, insurance, HOA, estimated PMI when applicable, plus estimated cash-to-close.
Does calculator use live rate?
No. Interest rate entered by user. Default 6.75% is example only, not current quote.
Does calculator calculate DTI?
Partially. Calculates housing-expense ratio using estimated housing payment and gross monthly income. Does not calculate complete back-end DTI because does not collect all recurring debts.
What is conforming loan limit?
National baseline conforming loan limit for one-unit property is $832,750 in most of the U.S. Higher limits apply in high-cost areas.
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Written and reviewed by MM Ahmed — FinProUSA Editorial Team
Senior Finance Writer | Content reviewed for Accuracy and Compliance, 10 years experience | Editorial Methodology
U.S. personal-finance calculator content prepared for educational purposes using publicly available authoritative sources, documented calculations, and page-specific methodologies. Results are estimates based on the information and assumptions entered and do not constitute financial, tax, legal, or investment advice.
Last reviewed: October 10, 2026 | Fact-checked for calculations, IRS 2026 brackets, and methodology | Reviewed for content, calculations, sources, and methodology.
Sources: IRS.gov, CFPB, SSA.gov, FHFA — linked on each applicable page.
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