The short answer: at a 6.5% rate, a $675,000 30-year fixed mortgage costs $4,266.46 a month in principal and interest; at 7%, $4,490.79. On a 15-year term at 6.5% the payment is $5,879.97. Taxes, insurance, HOA and mortgage insurance (if you put less than 20% down) come on top — open this loan in the full calculator to add them and see the complete amortization schedule.
| Rate | 30-year | 20-year | 15-year |
|---|---|---|---|
| 5.00% | $3,623.55 | $4,454.70 | $5,337.86 |
| 5.25% | $3,727.37 | $4,548.45 | $5,426.17 |
| 5.50% | $3,832.58 | $4,643.24 | $5,515.31 |
| 5.75% | $3,939.12 | $4,739.06 | $5,605.27 |
| 6.00% | $4,046.97 | $4,835.91 | $5,696.03 |
| 6.25% | $4,156.09 | $4,933.77 | $5,787.60 |
| 6.50% | $4,266.46 | $5,032.62 | $5,879.97 |
| 6.75% | $4,378.04 | $5,132.46 | $5,973.14 |
| 7.00% | $4,490.79 | $5,233.27 | $6,067.09 |
| 7.25% | $4,604.69 | $5,335.04 | $6,161.82 |
| 7.50% | $4,719.70 | $5,437.75 | $6,257.33 |
At 6.5%, interest alone on $675,000 runs about $3,656.25 per month — roughly $120.21 every day. That's the number amortization slowly kills: each payment shrinks the balance, so each month a little less goes to interest and a little more to principal. See the month-by-month schedule, or try our daily interest calculator for per-diem closing math.
Principal and interest is the floor, not the payment. A realistic budget adds property taxes, homeowners insurance, HOA dues, and — under 20% down — mortgage insurance, which our full calculator prices the way a lender does: FHA and USDA from the official tables, VA's funding fee, and conventional PMI by credit score.
A common guideline caps total housing costs near 28–36% of gross income, but real qualifying depends on your full debt picture, credit and loan program. Build the complete payment in the calculator, then ask a licensed professional — Phil answers questions free.
With 20% down, a $675,000 loan buys about $843,750 of house; with 5% down, about $710,526. Enter your own down payment in the payment calculator and the price, loan and LTV solve automatically.