Mortgage Calculator
Get the number you need, with the working shown.
What is the Mortgage Calculator?
The Mortgage Calculator works out your total monthly housing payment — principal, interest, property tax, home insurance and HOA dues together — from your home price, down payment, interest rate and term. Unlike a plain loan calculator, it separates the loan itself (principal and interest, using the standard amortization formula) from the other costs that make up a real monthly mortgage bill, and lets you model an extra monthly payment to see exactly how many months and how much interest it would save. Enter your numbers and you get a single estimated monthly payment, a full amortization schedule, and — if you add one — a direct comparison of the standard payoff against paying extra toward principal.
A mortgage payment is rarely just principal and interest. Property tax and homeowner's insurance are usually collected monthly through an escrow account alongside the loan payment, and HOA dues, where they apply, are a separate fixed cost on top of all of it. This calculator adds all four together into one realistic monthly figure, rather than showing only the loan's principal-and-interest portion the way a generic loan calculator would.
Why use a free mortgage calculator?
Total monthly payment, not just principal and interest
Property tax, home insurance and HOA dues are added to the loan payment, giving a realistic total rather than a partial figure that undersells the true monthly cost.
Extra payment modelling built in
Add a monthly extra payment and see exactly how many months sooner the loan is paid off and how much total interest it saves, computed from a full parallel amortization schedule rather than a rough estimate.
Down payment percentage shown live
As you adjust the down payment amount, the percentage of the home price it represents updates immediately — useful for tracking against the 20% threshold that typically avoids PMI.
Full amortization schedule
Every monthly payment across the full term is broken into principal, interest, any extra payment, and remaining balance.
Balance-over-time chart
A visual payoff curve makes it immediately clear how much faster the loan balance drops with an extra payment applied, compared to the standard schedule.
How do you use the Mortgage Calculator?
- 1
Enter home price and down payment
The difference between the two is your loan principal. The down payment percentage of the home price is shown automatically as you type.
- 2
Enter the interest rate and term
Use the APR quoted by your lender, and the loan term in years — typically 15 or 30 for a US mortgage.
- 3
Add property tax, insurance and HOA
Enter your annual property tax and insurance, and any monthly HOA dues, so the total monthly payment reflects the full real cost, not just the loan.
- 4
Try an extra monthly payment
Enter an extra amount to see exactly how many months sooner the loan pays off and how much total interest it saves, compared side by side with the standard schedule.
- 5
Review the full schedule
Expand the amortization table to see every payment's principal, interest, extra amount and remaining balance across the entire loan term.
How is mortgage calculator calculated?
M = P × [r(1+r)ⁿ] ÷ [(1+r)ⁿ − 1], then Total monthly = M + Tax/12 + Insurance/12 + HOAWhere:
- M
- Monthly principal and interest payment on the loan itself
- P
- Loan principal — home price minus down payment
- r
- Monthly interest rate — the annual rate (APR) divided by 100, then divided by 12
- n
- Total number of monthly payments — the loan term in years multiplied by 12
- Tax, Insurance, HOA
- Annual property tax and annual insurance divided by 12, plus monthly HOA dues, added on top of M
The simple version
First calculate the loan payment itself the same way any fixed-rate loan is calculated — spread the borrowed amount and its interest evenly across every payment. Then add your property tax and insurance, converted from yearly to monthly amounts, plus any HOA dues, to get the number you'll actually pay each month. If you add extra principal payments, the calculator re-runs the schedule with that extra amount applied every month, which shortens the loan and reduces total interest.
What does it look like in practice?
A standard 30-year mortgage
Input
$400,000 home, $80,000 down (20%), 6.5% APR, 30-year term, $4,800/yr property tax, $1,500/yr insurance
Result
Loan amount: $320,000 · Principal & interest ≈ $2,022/mo · Plus $400 tax + $125 insurance ≈ $2,547/mo total
A 20% down payment on a $400,000 home avoids most lenders' PMI requirement, which typically applies below 20% down.
The effect of an extra payment
Input
Same loan, with an extra $300/month applied to principal from the first payment onward
Result
Payoff time drops from 30 years to roughly 21 years — about 8.8 years sooner — saving an estimated $130,000–$140,000 in total interest
The exact figures depend on the month-by-month schedule the calculator runs, since extra payments compound: each one reduces the balance interest is calculated on for every remaining month.
Shorter term, same home price
Input
Same $320,000 loan at 6.5% APR, but a 15-year term instead of 30
Result
Principal & interest payment rises to roughly $2,788/mo, but total interest over the life of the loan drops by more than half
Shorter terms trade a meaningfully higher monthly payment for a large reduction in total interest paid — the same tradeoff shown on the Loan Calculator, just at mortgage scale.
How accurate is it?
The principal-and-interest portion uses the exact standard amortization formula run to full precision, matching how lenders calculate a fixed-rate mortgage payment. Property tax, insurance and HOA are added exactly as entered — this calculator does not look them up automatically, since actual rates vary by county, insurer and building.
- This is an estimate for planning, not a lender-issued quote. Actual mortgage offers depend on your credit profile, the specific loan program, points paid to buy down the rate, and lender-specific fees not modelled here.
- PMI (private mortgage insurance), typically required when the down payment is below 20%, is not automatically calculated — factor it in separately if your down payment is under that threshold, since it can add a meaningful amount to the true monthly cost.
- Property tax and insurance are treated as flat, unchanging annual amounts across the loan term. In reality, both typically rise over time, so the total monthly payment shown is most accurate for the near term rather than 15–30 years out.
- Extra-payment savings are computed by running a second, complete amortization schedule with the extra amount applied every month from the start — not estimated with a shortcut formula — so the months-saved and interest-saved figures reflect the actual compounding effect.
What should you know before using it?
What each part of the total monthly payment covers:
| Component | What it is |
|---|---|
| Principal & interest | The loan payment itself — repays the amount borrowed plus interest, calculated with the standard amortization formula. |
| Property tax | Set by your local government, usually billed annually or semi-annually but commonly collected monthly through escrow alongside your mortgage payment. |
| Home insurance | Required by virtually all mortgage lenders to protect the property (and their collateral) against damage or loss. |
| PMI (not auto-calculated) | Private mortgage insurance, typically required below 20% down, protects the lender if you default. Add it manually as an estimated monthly cost if it applies to you. |
| HOA dues | A fixed monthly or annual fee for properties within a homeowners association, separate from and in addition to the loan and tax/insurance costs. |
| Extra payment | Optional additional principal paid each month, on top of the required payment — the fastest lever for reducing total interest paid over the loan's life. |
Which tools relate to the mortgage calculator?
The mortgage calculator is one of 21 calculators on this site. These are the ones most often used alongside it — either because they handle the next step in the same job, or because they answer a question this tool raises.
Loan Calculator
Uses the same core amortization formula for any fixed-rate instalment loan, without the mortgage-specific costs — property tax, insurance, HOA and PMI — this tool adds.
GPA Calculator
If student debt is part of your broader financial picture alongside a mortgage, model it separately with the same amortization principles.
Bandwidth Calculator
Once you've budgeted your monthly housing cost, plan other fixed monthly household expenses, like internet service, alongside it.
When should you use a mortgage calculator?
Because the mortgage calculator runs entirely in your browser, it suits work you would not want to hand to a third-party server — client files, unpublished drafts, anything under an NDA. These are the situations people reach for it in most often.
Home shopping budget planning
Check the real total monthly cost — not just principal and interest — of homes at different price points before making an offer.
Deciding on a 15-year vs 30-year term
Compare the higher monthly payment of a 15-year mortgage against the lower payment but much higher lifetime interest cost of a 30-year term, using real numbers for your specific loan amount.
Evaluating whether to pay extra toward principal
See the exact months-saved and interest-saved from committing to a specific extra monthly payment, before deciding whether that money is better used elsewhere.
Refinancing comparisons
Model your current loan's remaining balance against a potential new rate and term to see whether refinancing would actually lower your total cost.
Frequently asked questions
How is a mortgage payment calculated?
What is PMI and why isn't it calculated automatically?
How much does an extra monthly payment actually save?
Should I choose a 15-year or 30-year mortgage?
Does this calculator include property tax and insurance automatically?
Why is my estimated payment different from what my lender quoted?
Is the mortgage calculator safe to use?
This tool runs entirely inside your browser. Your text, files and settings are processed on your own device and are never uploaded to our servers — there is nothing for us to store, log or leak. You can confirm it yourself: open your browser DevTools, switch to the Network tab, and use the tool. You will not see an upload request. It also means the tool keeps working if your connection drops mid-task.
Where do these figures come from?
Every method, threshold and standard this page relies on, with a link to the document that defines it. Check them — a tool that will not show its sources is asking you to take its word for it.
- 1Regulation Z (Truth in Lending), Appendix J to Part 1026 — Annual Percentage Rate Computations for Closed-End Credit Transactions
Consumer Financial Protection Bureau · 2011
Supports: The standard fixed-payment amortization formula used for the principal-and-interest portion of the monthly payment.
- 2What is mortgage insurance and how does it work?
Consumer Financial Protection Bureau
Supports: The claim that PMI is typically required when the down payment is below 20% of the home price.
- 3What is an escrow or impound account?
Consumer Financial Protection Bureau
Supports: The statement that property tax and homeowner's insurance are typically collected monthly through escrow alongside the loan payment.
Read more about mortgage calculator
How to Plan a Smart Down Payment Online Before Touring Any Property
Learn how to plan a smart down payment online with trusted calculators for confident home buying decisions. Completely free, fast, and no signup required.
3 min read
How to Plan Monthly Mortgage Payments Before Visiting Open Houses
Learn how to plan monthly mortgage payments online with smart calculators and budgeting tips for stress-free home buying. Free, accurate, and no signup needed.
3 min read
How Real Estate Agents Use Free Image Tools to Sell Homes Faster Online
Discover how real estate agents use free image tools to optimize, brand, and promote listings without expensive software. Free, accurate, and no signup needed.
2 min read
More on the Smart SEO Toolz blog.
Need something this tool can’t do?
If you need a feature added, spotted something wrong, or want a custom tool or website built for your business, tell us. We read every message and we build what people actually ask for.
More tools
Tools that pair well with this one
Browse every category
- SEO Tools31
- Keyword Tools7
- Domain & IP Tools18
- Text Tools20
- Writing Tools12
- Image Tools31
- PDF Tools17
- Unit Converters14
- Calculators21
- Developer Tools13
- Generators16
- Design & CSS Tools6
- Games8
Looking for something else? See all 214 tools, browse the full site index or read the guides on our blog.