Quick Answer: On a $400,000 home with 20% down at 6.5% for 30 years, your monthly mortgage payment (principal + interest) is approximately $2,023. Add property taxes (~$367/mo), homeowners insurance (~$100/mo), and your total PITI payment is roughly $2,490/month.
How to Use the Mortgage Calculator
Enter the home price, down payment percentage, interest rate, and loan term. Add your property tax rate and annual insurance costs. If your down payment is under 20%, PMI is automatically included.
The calculator instantly breaks down your total monthly payment into principal, interest, taxes, insurance, and PMI (PITI). It also shows total interest over the loan life and a 5-year amortization preview so you can see how your balance decreases over time.
Mortgage Payment Formula
The standard amortization formula used by every lender:
M = P × [r(1+r)^n] / [(1+r)^n − 1]
- M = Monthly principal + interest payment
- P = Loan amount (home price − down payment)
- r = Monthly interest rate (annual rate ÷ 12)
- n = Total number of payments (years × 12)
Example: $320,000 loan at 6.5% for 30 years → r = 0.065/12 = 0.005417, n = 360. Monthly P&I = $2,023. Total interest over 30 years = $408,280.
Your full PITI payment adds: property taxes + homeowners insurance + PMI (if applicable).
15-Year vs 30-Year Mortgage: Which Is Better?
On a $400,000 loan at 6.0%, here is how the two most common loan terms compare:
| Metric | 30-Year Fixed | 15-Year Fixed |
|---|---|---|
| Monthly Payment (P&I) | $2,398 | $3,375 |
| Total Interest Paid | $463,353 | $207,575 |
| Interest Savings vs 30-yr | — | $255,778 |
| Years to Pay Off | 30 years | 15 years |
| Income Needed (28% rule) | ~$103,000/yr | ~$145,000/yr |
| Equity After 5 Years | ~$28,000 | ~$75,000 |
The 15-year saves $255,778 in interest but requires $977 more per month. If you can afford the higher payment, the 15-year is almost always the better financial decision long-term.
Down Payment Impact: 3% vs 5% vs 20%
On a $400,000 home at 6.5% for 30 years, your down payment dramatically affects your monthly cost:
| Metric | 3% Down (FHA) | 5% Down | 20% Down |
|---|---|---|---|
| Down Payment Amount | $12,000 (3%) | $20,000 (5%) | $80,000 (20%) |
| Loan Amount | $388,000 | $380,000 | $320,000 |
| Monthly P&I (6.5%) | $2,453 | $2,403 | $2,023 |
| PMI Required? | Yes (~$194/mo) | Yes (~$190/mo) | No |
| Total Monthly (PITI+PMI) | ~$3,147 | ~$3,093 | ~$2,523 |
| PMI Drops Off At | ~Year 10 | ~Year 9 | N/A |
The 20% down payment saves you ~$624/month vs 3% down — that is $7,488/year. If you can reach 20%, do it.
2026 Mortgage Rate Outlook
As of June 2026, 30-year fixed mortgage rates are approximately 6.25%–6.75%. Here is what is driving rates and what to expect:
- Federal Reserve: The Fed held rates steady through early 2026. Potential cuts are expected in late 2026, which would gradually lower mortgage rates.
- 15-year fixed: Currently ~5.5%–6.0% — roughly 0.5–0.75% lower than 30-year rates.
- ARM rates: 5/1 ARMs starting around 5.5%–6.0% — attractive if you plan to move within 5–7 years.
- Rate lock strategy: Lock your rate when you find a property. Most lenders offer 30–60 day locks. Some offer float-down options if rates drop during your lock period.
Real-Life Scenarios with Step-by-Step Math
Scenario 1: First-Time Buyer with FHA Loan
Profile: Taylor and Jordan, combined income $95,000/year. Looking at a $350,000 home with 3.5% down payment (FHA loan). Current 30-year FHA rate at 6.25%. Property taxes at 1.1%, insurance at $1,000/year.
Calculation:
- Down Payment = $350,000 × 3.5% = $12,250
- Loan Amount = $350,000 − $12,250 = $337,750
- Monthly Rate = 6.25% ÷ 12 = 0.5208%
- Number of Payments = 30 × 12 = 360
- Monthly P&I = $337,750 × [0.005208(1.005208)^360] ÷ [(1.005208)^360 − 1] = $2,079
- Property Taxes = ($350,000 × 1.1%) ÷ 12 = $321/mo
- Insurance = $1,000 ÷ 12 = $83/mo
- MIP (FHA) = $337,750 × 0.55% ÷ 12 = $155/mo (FHA requires MIP for life of loan)
- Total Monthly Payment (PITI+MIP) = $2,638
Affordability check — 28% rule: $95,000 ÷ 12 = $7,917/month gross. Max PITI at 28% = $2,217. Their payment of $2,638 exceeds the 28% guideline, meaning they may be house-poor. They might need to look at $300,000–$320,000 homes, or increase their down payment to reduce the loan amount.
Scenario 2: Conventional Loan with 20% Down
Profile: David, $130,000/year salary, buying a $450,000 home with 20% down. 30-year conventional at 6.5%. Property taxes at 1.2%, insurance at $1,200/year.
Calculation:
- Down Payment = $450,000 × 20% = $90,000 (no PMI!)
- Loan Amount = $450,000 − $90,000 = $360,000
- Monthly P&I at 6.5% = $2,275
- Property Taxes = ($450,000 × 1.2%) ÷ 12 = $450/mo
- Insurance = $1,200 ÷ 12 = $100/mo
- PMI = $0 (20% down eliminates PMI)
- Total Monthly Payment (PITI) = $2,825
Affordability check: $130,000 ÷ 12 = $10,833/month. 28% = $3,033. PITI of $2,825 is under the 28% threshold. With no PMI, David saves ~$180/month compared to a 15% down scenario. Total savings over 5 years: $10,800 in avoided PMI + lower loan balance.
Scenario 3: 15-Year vs 30-Year Tradeoff
Profile: Emma, $150,000/year, buying a $500,000 home with 20% down ($100,000). She is debating between a 30-year at 6.5% and a 15-year at 5.75%.
- 30-year: Monthly P&I = $2,529. Total interest over 30 years = $510,290.
- 15-year: Monthly P&I = $3,319. Total interest over 15 years = $197,450.
- Interest savings: $510,290 − $197,450 = $312,840 saved!
- Extra monthly cost: $3,319 − $2,529 = $790/month
By paying an extra $790/month for 15 years, Emma saves $312,840 in interest — that is a $312,840 return on $142,200 in extra payments ($790 × 180 months). An effective return of 220%. If she invests that $790/month instead at 7% return, she would have ~$255,000 after 15 years. The 15-year mortgage is still the clear winner for guaranteed savings.
Key Considerations for Home Buyers
- The 28/36 rule: Your housing payment (PITI) should not exceed 28% of gross monthly income. Total debt payments should not exceed 36%. Lenders use this to qualify you.
- PMI: Required when down payment is under 20%. Costs 0.3%–1.5% of the loan annually. Automatically cancels when you reach 22% equity (or request cancellation at 20%).
- Property taxes: US average is ~1.1% annually, but varies widely — New Jersey averages 2.4%, Hawaii averages 0.3%. Always check your specific county rate.
- Closing costs: Typically 2%–5% of the purchase price. On a $400,000 home, budget $8,000–$20,000 for appraisal, origination fees, title insurance, and prepaid escrow.
- Credit score impact: A 740+ score gets you the best rates. Going from 680 to 740 can save 0.5%–0.75% on your rate — that is $100–$150/month on a $400,000 loan.
- Maintenance budget: Budget 1%–2% of home value annually for repairs and maintenance. A $400,000 home needs $4,000–$8,000/year set aside.
Common Mortgage Mistakes to Avoid
- Not shopping multiple lenders. Getting quotes from 3–5 lenders can save 0.25%–0.5% on your rate — worth $20,000–$40,000 over 30 years on a $400,000 loan.
- Ignoring total PITI. Many buyers focus only on the principal + interest payment and forget taxes, insurance, and PMI. Always calculate the full PITI.
- Changing jobs before closing. Lenders verify employment right before closing. A job change can delay or kill your loan approval.
- Opening new credit accounts. New credit inquiries lower your score and increase your DTI. Avoid any new credit from pre-approval to closing.
- Skipping the home inspection. A $400–$600 inspection can reveal $10,000–$50,000 in hidden problems. Never skip it.
Frequently Asked Questions
How is a mortgage payment calculated?
What is a good mortgage rate in 2026?
What is PMI and when is it required?
How does loan term affect monthly payment?
How much house can I afford on $100,000 salary?
What credit score do I need for a mortgage?
What are closing costs and how much should I expect?
📋 Data Sources & Methodology
- CFPB — Owning a Home: Mortgage shopping toolkit and payment estimator — consumerfinance.gov
- Freddie Mac PMMS: Weekly Primary Mortgage Market Survey — freddiemac.com/pmms
- FHA Mortgage Insurance: UFMIP and MIP guidelines — hud.gov
- Fannie Mae: Loan-level price adjustment (LLPA) matrix — fanniemae.com
Last Updated: June 2026. Mortgage rate figures based on Freddie Mac PMMS weekly survey. Calculations use the standard amortization formula (M = P × [r(1+r)^n] / [(1+r)^n − 1]). PMI rates vary by lender and credit score. Property tax estimates based on US county averages.
Related Tools
- Home Affordability Calculator — How much house can you afford based on your income and debts?
- Mortgage Refinance Calculator — Should you refinance? See your break-even point and savings.
- Amortization Calculator — Full amortization schedule with every payment broken down.
- DTI Ratio Calculator — Calculate your debt-to-income ratio before applying.