A $600k home with a $120,000 down payment leaves a $480,000 loan. To keep the $4,013 total 30-year payment at or under 28% of gross income (the calculator's default housing ratio), household income would need to be roughly $171,975 a year, before other debts. Choosing the 15-year term instead cuts lifetime interest by about $432,828 ($716,432 vs $283,604), at the cost of a $919/month higher payment.
| Term | Rate | Principal & interest | Total monthly payment | Total interest |
|---|---|---|---|---|
| 30-year | 7.4% | $3,323 | $4,013 | $716,432 |
| 15-year | 6.73% | $4,242 | $4,932 | $283,604 |
Property taxes add $450/month and insurance adds $239/month in this example, on top of principal and interest, for either term.
Open the 30-year example Open the 15-year example
Source references: Tax Foundation: Property Taxes by State and County, 2026 Insurance.com: Average Homeowners Insurance Rates by State (2026)
Rate reference as of 10/8/2026. Educational software; no professional review claimed.