A $300,000 fixed-rate mortgage at 8% APR paid over 10 years costs $3,639.83 per month. Over the life of the loan you would pay $136,779 in interest — 46% of the amount borrowed.
The 8% rate on this page is 2.21 points above this week's national average of 5.79% for a 15-year fixed mortgage (Freddie Mac PMMS, July 2, 2026).
| Period | Principal paid | Interest paid | Balance |
|---|
| Scenario | Monthly | Total interest |
|---|---|---|
| $300,000 at 4% (10yr) | $3,037.35 | $64,482 |
| $300,000 at 4.25% (10yr) | $3,073.13 | $68,775 |
| $300,000 at 4.5% (10yr) | $3,109.15 | $73,098 |
| $300,000 at 4.75% (10yr) | $3,145.43 | $77,452 |
| $300,000 at 5% (10yr) | $3,181.97 | $81,836 |
| $300,000 at 5.25% (10yr) | $3,218.75 | $86,250 |
| $300,000 at 5.5% (10yr) | $3,255.79 | $90,695 |
| $300,000 at 5.75% (10yr) | $3,293.08 | $95,169 |
| $300,000 at 6% (10yr) | $3,330.62 | $99,674 |
| $300,000 at 6.25% (10yr) | $3,368.40 | $104,208 |
| $300,000 at 6.5% (10yr) | $3,406.44 | $108,773 |
| $300,000 at 6.75% (10yr) | $3,444.72 | $113,367 |
| $300,000 at 7% (10yr) | $3,483.25 | $117,991 |
| $300,000 at 7.25% (10yr) | $3,522.03 | $122,644 |
| $300,000 at 7.5% (10yr) | $3,561.05 | $127,326 |
| $300,000 at 7.75% (10yr) | $3,600.32 | $132,038 |
| $300,000 at 8% (10yr) ← this page | $3,639.83 | $136,779 |
| $300,000 at 8.5% (10yr) | $3,719.57 | $146,348 |
| $300,000 at 9% (10yr) | $3,800.27 | $156,033 |