Mortgage Calculator | Free Monthly Payment & Affordability Tool
Calculate your monthly mortgage payment, find out how much house you can afford, and compare 15 vs 30 year terms.
📖 Want to understand your results?
Read our complete guide to the Mortgage Calculator — with real-world examples, expert insights, and pro tips.
— Advertisement —
Below Result
Responsive
Slot: placeholder-calc-bottom-slot
Understanding Your Mortgage Payment
A mortgage payment typically includes four components, often called PITI:Principal & Interest (P&I), Property Taxes, Homeowners Insurance, and PMI (Private Mortgage Insurance) if your down payment is less than 20%.
Understanding each component helps you accurately budget for homeownership and avoid surprises when you receive your monthly statement.
Mortgage Payment Formula
Where: M = Monthly Payment, P = Loan Principal
r = Monthly Interest Rate (Annual ÷ 12)
n = Total number of payments (Years × 12)
For example, a $300,000 loan at 6.5% for 30 years gives a monthly P&I payment of $1,896. Adding estimated taxes ($300), insurance ($100), and PMI ($150) brings the total to approximately $2,446/month.
The 28/36 Rule for Affordability
Lenders use the 28/36 Rule to determine how much you can borrow:
- 28% Front-End Ratio: Your total monthly housing costs (PITI) should not exceed 28% of your gross monthly income.
- 36% Back-End Ratio: Your total debt payments (housing + car loans + student loans + credit cards) should not exceed 36% of your gross monthly income.
For an $80,000 annual income ($6,667/month), the maximum housing payment would be $1,867/month (28%), and total debt payments should stay under $2,400/month (36%).
15-Year vs 30-Year Mortgage
| Feature | 15-Year | 30-Year |
|---|---|---|
| Monthly Payment | Higher (~$2,614) | Lower (~$1,896) |
| Total Interest | ~$170,500 saved | ~$382,600 total |
| Interest Rate | Typically 0.5-1% lower | Higher rate |
| Equity Building | Fast | Slow |
| Best For | Higher income, shorter timeline | Lower payments, flexibility |
On a $300,000 loan at 6.5%, choosing a 15-year term saves approximately $170,500 in interest compared to a 30-year term, but requires a $718 higher monthly payment.
Tips to Lower Your Mortgage Payment
- Increase your down payment: A 20% down payment eliminates PMI and lowers your loan amount.
- Improve your credit score: A 760+ credit score qualifies you for the best interest rates.
- Shop for rates: Compare offers from 3-5 lenders — even a 0.25% rate difference saves thousands over the loan term.
- Consider points: Paying discount points upfront lowers your interest rate if you plan to stay long-term.
- Choose a shorter term: If you can afford it, a 15-year mortgage saves significant interest.
Mortgage Calculator Pros & Cons
Pros
- ✅ Instant PITI monthly payment breakdown
- ✅ 28/36 rule affordability calculator
- ✅ Free forever — no subscriptions
- ✅ Works offline after page load
- ✅ No sign-up or email required
Cons
- ✗ No Excel/CSV export option
- ✗ No dedicated mobile app
Frequently Asked Questions
How are mortgage payments calculated?
Monthly payments = Principal & Interest + Property Taxes + Insurance + PMI (if down payment < 20%). P&I uses the loan amortization formula based on your loan amount, interest rate, and term.
How much house can I afford?
Use the 28/36 rule: housing costs shouldn't exceed 28% of gross monthly income, and total debt shouldn't exceed 36%. Our affordability calculator uses these guidelines.
Should I choose a 15 or 30 year mortgage?
15-year mortgages have higher monthly payments but save tens of thousands in interest. 30-year mortgages have lower payments but cost more in total interest. Choose based on your budget and financial goals.
Reviewed by James Rodriguez, CFA
Finance & Investment AnalystChartered Financial Analyst with 10+ years in investment research and financial planning.
Footer Banner
Responsive
Slot: placeholder-footer-slot