A Mortgage Payment Calculator computes monthly mortgage payments and total interest. It applies the standard formula to the values you enter and returns the result instantly, without sending any data to a server. Borrowers use it to compare offers and to plan repayments.
Monthly payment, total interest, and payoff timeline.
M = P x r(1+r)^n / ((1+r)^n - 1) where r is the monthly rate and n is the number of months.
Get your full PITI: principal + interest + taxes + insurance + PMI.
A mortgage calculator turns your home price, down payment, interest rate, and loan term into a single monthly payment. Most US lenders include taxes and insurance in your monthly payment via an escrow account - that's the 'PITI' you actually pay. PMI applies when your down payment is under 20 percent of home price.
Enter home price and down payment to compute the loan amount. The calculator applies the standard amortization formula for principal and interest, divides annual taxes and insurance by 12 to add to escrow, and adds PMI if your down payment is under 20 percent.
Equated Monthly Installment is fixed monthly payment that pays off principal + interest over the term. The formula:
EMI = P x r x (1+r)^n / ((1+r)^n - 1)
where P = principal, r = monthly interest rate (annual / 12), n = total months. Every payment is the same amount, but the SPLIT between interest and principal shifts over time:
Going from a 3% rate to a 7% rate more than doubles total interest over the life of the loan. A 1 percentage point increase on a 30-year mortgage adds ~13-15% to total payments.
| Type | Description | Best when |
|---|---|---|
| 30-year fixed (US) | Same rate + payment for 30 years | You'll stay in the home 7+ years; rates are low; you want predictability |
| 15-year fixed (US) | Same rate, paid off twice as fast | You can afford 50% higher monthly payment; want to save 60-70% on interest |
| ARM / variable | Rate adjusts every 1-10 years to a benchmark + margin | You'll sell within the fixed period; current ARM rate is significantly lower than 30-fixed |
| Tracker (UK) | Rate = Bank of England base + margin | You expect base rate to fall; comfortable with payment uncertainty |
| Variable Canada | 5-year discounted variable | You can absorb 100-200 bp upside; want lowest opening rate |
Many loans require mortgage insurance when the down payment is below 20% (US PMI), 20% (Canada CMHC, mandatory below 20%), 20% (Australia LMI). This is insurance for the LENDER paid by the BORROWER. It typically costs 0.5%-1.5% of the loan annually and adds nothing to your equity. Strategies to avoid:
This calculator uses the following formula:
M = P × [c(1+c)^n] / [(1+c)^n - 1] where P=loan amount, c=monthly rate (annual÷12), n=months
The reason this formula works is rooted in the underlying physics, finance, or biology of the problem. Behind every calculator is a published, peer-reviewed equation or a widely accepted convention. We do not invent formulas; we apply standard ones from textbooks, government tables, professional bodies, and academic literature.
If you are curious about the math, the simplest way to verify is to plug in two known numbers and compare against a known result. The calculator should match published examples to within rounding precision.
Principal + Interest + Taxes + Insurance - the four components of your monthly mortgage payment when taxes and insurance are escrowed.
Conventional loans must auto-cancel PMI once you reach 78 percent loan-to-value. You can request earlier removal at 80 percent LTV with a current appraisal.
It avoids PMI but ties up cash. With high investment returns possible elsewhere, many buyers prefer 5 to 15 percent down even with PMI.
It varies by state - Hawaii is 0.3 percent, New Jersey is 2.5 percent. Use your local assessor's website for an accurate figure.
Banks often include processing fees, mortgage insurance, property tax escrow, or homeowner's insurance in the quoted 'monthly payment'. The calculator shows pure principal + interest only. Add ~$200-400/month for the escrow + insurance components in US/Canada/AU.
Compare: 20% down avoids PMI (~1% loan/year) and reduces principal you pay interest on. Investing the same amount might earn 7% historical equity returns long-term. If your mortgage rate is below 5%, investing usually wins. Above 7%, the down payment wins.
Mortgages compound monthly in most countries (US, UK, India). Canada compounds SEMI-annually (a quirk of Canadian law). The displayed rate is annual; the formula uses rate/12 except in Canada where it's slightly different.
In the US: usually yes - most conventional 30-year fixed mortgages have no prepayment penalty. In Canada and UK: there's often a 3-month-interest or interest-rate-differential penalty on fixed-rate loans. Check your specific loan agreement.
Interest rate is the cost of borrowing. APR (Annual Percentage Rate) includes the rate PLUS fees (origination, points, mortgage insurance), expressed as an equivalent annual cost. APR is the better comparison number when shopping lenders. APR is always equal to or higher than the rate.
It applies the standard formula. Accuracy is limited only by your input precision. For decisions with material consequences (taxes, medical, legal, structural), use the result as a starting point and verify with a qualified professional in the relevant field.
Yes. 100% free, no signup, no payment, no API key. The site is funded by display ads around the tool but not inside the calculation flow.
No. All inputs stay in your browser tab. Closing the tab discards them. The site uses Google Analytics for traffic measurement (anonymized) but the analytics never see what you type into the form.
Yes. The tool is responsive and tested on iOS Safari, Android Chrome, and major desktop browsers. Touch targets meet Apple's 44pt and Google's 48dp minimum.
Yes. Once the page has loaded, it works without internet. The calculation runs in JavaScript on your device.
Email hi@3tej.com with the URL of this page and a description of what you saw vs expected. We typically respond within 72 hours.
Take a screenshot or copy the output. The page doesn't generate shareable URLs for specific calculations - inputs stay in your browser only.
Most likely: different formula assumptions, different default values, different rounding rules, or different applicable rates. Check the methodology if both tools document it. Both can be valid for different scenarios.