$665/mo
Est. monthly payment
A $100,000 mortgage costs about $665/month at 7% interest over a 30-year loan. This covers principal and interest — once you add property taxes and homeowners insurance, the realistic monthly total is $825–$1,000. Down payment assumed at 0%; with 20% down ($20,000), the payment drops to $532/month and PMI is eliminated.
Adjust the numbers below to see how your payment changes:
Open Mortgage Calculator →On a $100,000 loan over 30 years, each 1% rate increase adds about $65–$70/month to your payment.
| Interest Rate | Monthly P&I | Total Interest (30yr) |
|---|---|---|
| 5.0% | $537 | $93,256 |
| 6.0% | $600 | $115,838 |
| 6.5% | $632 | $127,544 |
| 7.0% | $665 | $139,508 |
| 7.5% | $699 | $151,722 |
| 8.0% | $734 | $164,155 |
A bigger down payment lowers your monthly bill and total borrowing cost. At 20% down you also drop PMI.
| Down Payment | Loan Amount | Monthly P&I | Monthly Savings |
|---|---|---|---|
| 0% ($0) | $100,000 | $665 | — |
| 3.5% ($3,500) | $96,500 | $642 | $23 |
| 5% ($5,000) | $95,000 | $632 | $33 |
| 10% ($10,000) | $90,000 | $599 | $66 |
| 20% ($20,000) | $80,000 | $532 | $133 + no PMI |
| Loan Term | Monthly P&I | Total Interest | Total Paid |
|---|---|---|---|
| 30 years | $665 | $139,500 | $239,500 |
| 15 years | $899 | $61,700 | $161,700 |
The 15-year term costs $234/month more but saves $77,800 in total interest.
Principal and interest is only part of the picture. Here's a realistic monthly breakdown for a $100,000 mortgage at 7%:
PMI adds $50–$100/month if your down payment is below 20%. HOA fees can push the total higher. Use the mortgage calculator for a complete estimate.
At 7% interest over 30 years, expect about $665/month in principal and interest. Add taxes and insurance for a total closer to $825–$1,000/month.
The 28% DTI guideline puts the minimum at roughly $28,000–$32,000/year gross income. Lenders may approve slightly lower if you have minimal debt.
Putting 20% down ($20,000) leaves an $80,000 loan. At 7% over 30 years that's $532/month P&I — and you skip PMI entirely.
Each 1% change shifts your payment by about $65–$70/month. At 5%: $537/month. At 7%: $665/month. At 8%: $734/month. Over 30 years, that extra 1% costs $25,000+ in added interest.
At 7% over 30 years: approximately $139,500 in interest. You end up paying $239,500 total for a $100,000 loan. A 15-year term cuts interest to about $61,700.
The 15-year option runs $899/month vs. $665 for 30 years — $234 more monthly — but saves $77,800 in total interest. Pick 15 years if your budget allows; stick with 30 for more breathing room. Compare both.