Mortgage & Housing

Mortgage Calculator

Estimate fixed-rate mortgage payments with either equal-payment amortization or equal-principal declining payments.

Equal payment = P × r / (1 - (1 + r)^-n); equal principal first payment = P / n + P × r

What is Mortgage Calculator?

Estimate fixed-rate mortgage payments with either equal-payment amortization or equal-principal declining payments.

Estimate principal-and-interest payment before speaking with a lender.
Compare how rate, term, and down payment change monthly payment and total interest.
Understand the cash-flow difference between equal payment and equal principal repayment.
Prepare realistic numbers for a household budget or home-buying discussion.

Scope and country basis

This mortgage calculator is a first-pass principal-and-interest planning tool for English-speaking users. It uses the home price, down payment, interest rate, term, and repayment method you enter; it does not hard-code one country's taxes, insurance, grants, or lending rules.

Mortgage rules vary by market. U.S. users often need property tax, homeowners insurance, PMI, HOA fees, and closing costs. U.K. users may need stamp duty and local lending rules. Canadian mortgages may use different compounding conventions. Use the selector for currency display, then verify local rules before making a borrowing decision.

What each input means

Home price: The purchase price of the property before taxes, closing costs, insurance, repairs, or moving costs.
Down payment: The cash paid upfront. Loan principal is estimated as home price minus down payment.
Annual interest rate: Enter the quoted annual mortgage rate, such as 6.5 for 6.5%.
Loan term: Enter the repayment period in years. Longer terms lower the payment but usually increase total interest.
Repayment method: Equal payment keeps the payment stable. Equal principal starts higher, declines over time, and usually lowers total interest.

Formula and interpretation

Equal payment formula: payment = principal x monthly rate x (1 + monthly rate)^months / ((1 + monthly rate)^months - 1). Equal principal formula: monthly principal = principal / months; month n interest = remaining principal x monthly rate; month n payment = monthly principal + month n interest.

Use the result to compare monthly cash flow and total interest. For equal payment, focus on the fixed payment and total interest. For equal principal, focus on the first payment because that is the affordability stress point.

Key concepts

Principal: The amount borrowed after subtracting the down payment from the home price.
Interest: The cost paid to the lender for borrowing the principal.
Equal payment: A stable monthly payment where early payments are more interest-heavy.
Equal principal: A repayment style with fixed principal each month and declining interest over time.

How to read the result

A lower monthly payment can still mean a much higher lifetime interest cost.
Equal principal should be judged by the first payment, not the average payment.
A small rate change can materially affect a long mortgage, so test a higher-rate scenario.
Principal-and-interest is not the same as total homeownership cost.

How to use it

Enter the property price and down payment to estimate the loan principal.
Enter the annual rate and term from your lender quote or planning assumption.
Compare equal payment and equal principal to see cash-flow stability versus total interest.
Add taxes, insurance, PMI, HOA, maintenance, and closing costs before deciding affordability.
Use related affordability, amortization, and rent-vs-buy tools for the next layer of analysis.

Common mistakes

Comparing rent with only principal and interest while ignoring taxes, insurance, PMI, HOA, maintenance, and closing costs.
Using a teaser rate instead of the actual quoted annual rate.
Choosing a longer term only for the lower payment without checking total interest.
Assuming one country's mortgage rules apply everywhere.

Suggested workflow

Use this page for principal and interest.
Use the mortgage-with-taxes-PMI calculator for fuller monthly housing cost.
Use the affordability calculator to connect payment to income and debt.
Use rent-vs-buy to compare multi-year housing choices.

Method and review boundary

This calculator runs a local estimate from the inputs and formula shown on this page. It does not retrieve live rules, rates, underwriting decisions, or quotes from banks, tax authorities, insurers, or other providers. Last reviewed: July 24, 2026.

For tax, lending, insurance, retirement, investment, or contract decisions, verify official guidance, the relevant agreement, and a formal quote for your location. Use this result to compare scenarios and prepare questions, not as financial, tax, investment, or legal advice.

Official references and applicability

Payment formula is general. U.S. disclosures and China LPR references are listed separately; actual rates, fees, taxes, and approval rules depend on location and lender.

CFPB Loan Estimate Explainer — Consumer Financial Protection Bureau
People's Bank of China LPR releases — People's Bank of China

Sources checked July 24, 2026. Rules and source pages can change; review them again before formal use.

Notes

This calculator does not include property tax, insurance, PMI, HOA, maintenance, closing costs, or prepayment penalties.
It is a planning estimate, not a lender approval or financial advice.
Local law, tax, compounding, and mortgage product rules can change the final result.

FAQ

Is this calculator mainly for the U.S.?

The basic principal-and-interest math is broadly useful, but local mortgage costs and rules differ. Calculator.net labels its U.S. mortgage page as mainly intended for U.S. residents; this page keeps policy-sensitive costs as separate user assumptions.

What is the difference between equal payment and equal principal?

Equal payment keeps the monthly payment stable. Equal principal repays the same principal each month, so the first payment is higher and later payments decline.

Does this include taxes, insurance, PMI, or HOA fees?

No. This basic page calculates principal and interest. Use a total housing cost calculator when you need taxes, insurance, PMI, HOA, or other ownership costs.

Why is total interest so high on a long mortgage?

Interest is charged over many months. Extending the term usually lowers the monthly payment but gives interest more time to accumulate.

Can I use this for the U.K., Canada, or Australia?

You can use it for a rough principal-and-interest estimate if you enter the correct local rate and currency, but you should verify local compounding, taxes, fees, and lending rules.

Is Mortgage Calculator free?

Yes. It runs in your browser and does not require an account.