Interactive Mortgage Calculator: Plan Your Home Loan with Precision
Use the mortgage calculator to preview loan size, monthly payment, and lifetime interest. Enter property price, down-payment %, term, and rate, then press Calculate. Example: a $1.7 million home, 12 % down, 30 years, 3.8 % annual interest ≈ $6,970/month. Average U.S. 30-year fixed rate was 6.79 % in June 2024 (Freddie Mac PMMS, 2024).
Mortgage Calculator
Results
Down Payment:
Loan Amount:
Month
Amortization
Interest
Total Payment
Loan Left
★ Add to Home Screen
×
Follow these steps:
Tap the Share button at the bottom of the browser
Scroll down and tap “Add to Home Screen”
Tap “Add” to confirm
Follow these steps:
Tap the menu icon (⋮) in the top right
Tap “Add to Home screen”
Tap “Add” to confirm
Follow these steps:
Click the menu icon (⋮) in the top right
Click “Bookmarks”
Click “Bookmark this tab” or press Ctrl+D (Cmd+D on Mac)
Is this tool helpful?
Thanks for your feedback!
How to use the tool
Property price – type 1 700 000 or 950 000. Use the full purchase price before fees.
Down-payment % – enter 12 or 28. The field accepts 0–100 %.
Term (years) – try 30 or 8. The calculator covers 1–50 years.
Interest % – input 3.8 or 5.4. Use your lender’s annual fixed rate.
Press “Calculate” – results show down payment, loan amount, monthly payment, and a 100 % amortization table.
The payment formula
Monthly payment M follows the standard amortization equation:
$$
M = P \; rac{r(1+r)^n}{(1+r)^n – 1}
$$
P = loan principal (price − down payment).
r = monthly interest = annual rate ÷ 12.
n = total payments = years × 12.
Example 1
Price 1 700 000, down 12 %, 30 years, 3.8 % rate:
P = 1 496 000
r = 0.038/12 ≈ 0.003167
n = 360
M ≈ $6 970
Example 2
Price 900 000, down 25 %, 10 years, 5.1 % rate:
P = 675 000
r = 0.051/12 ≈ 0.00425
n = 120
M ≈ $7 200
Quick-Facts
Average U.S. 30-year fixed rate: 6.79 % (Freddie Mac PMMS, 2024).
Standard loan terms: 15 or 30 years (Fannie Mae Selling Guide, 2024).
20 % down avoids private mortgage insurance (CFPB “Buying a House”, 2023).
Amortization formula from “Fundamentals of Financial Management” (Brigham & Ehrhardt, 2022).
FAQ
What is a mortgage calculator?
A mortgage calculator is an online tool that estimates monthly payments, total interest, and remaining balance using amortization math (CFPB, 2023).
How does down-payment size affect my loan?
A larger down payment reduces principal, lowers monthly cost, and eliminates private mortgage insurance once it reaches 20 % (CFPB, 2023).
Why use monthly rather than annual interest?
Lenders compound interest monthly; converting the annual rate to a monthly rate aligns the math with actual billing cycles (Federal Reserve, 2024).
Can I include taxes and insurance?
This calculator covers principal and interest only. Add estimated taxes and insurance separately for a full housing cost picture (HUD, 2024).
What happens if I pay extra each month?
Extra principal shortens the term and cuts interest. “Even $100 a month can save thousands” (Fannie Mae FAQ, 2024).
How accurate are the results?
The formula is industry standard; final numbers may vary slightly with rounding or lender fees (Brigham & Ehrhardt, 2022).
Which interest rate should I enter?
Use the Annual Percentage Rate quoted in your Loan Estimate; it includes fees rolled into the rate (CFPB TILA Guide, 2023).
What loan term is best for me?
Shorter terms cost more monthly but cut lifetime interest; 30-year terms trade lower payments for higher total cost (Freddie Mac, 2024).
Important Disclaimer
The calculations, results, and content provided by our tools are not guaranteed to be accurate, complete, or reliable. Users are responsible for verifying and interpreting the results. Our content and tools may contain errors, biases, or inconsistencies. We reserve the right to save inputs and outputs from our tools for the purposes of error debugging, bias identification, and performance improvement. External companies providing AI models used in our tools may also save and process data in accordance with their own policies. By using our tools, you consent to this data collection and processing. We reserve the right to limit the usage of our tools based on current usability factors. By using our tools, you acknowledge that you have read, understood, and agreed to this disclaimer. You accept the inherent risks and limitations associated with the use of our tools and services.
