A $300,000 fixed-rate mortgage at 8% APR paid over 20 years costs $2,509.32 per month. Over the life of the loan you would pay $302,237 in interest — 101% of the amount borrowed.
The 8% rate on this page is 1.57 points above this week's national average of 6.43% for a 30-year fixed mortgage (Freddie Mac PMMS, July 2, 2026).
| Period | Principal paid | Interest paid | Balance |
|---|
| Scenario | Monthly | Total interest |
|---|---|---|
| $300,000 at 4% (20yr) | $1,817.94 | $136,306 |
| $300,000 at 4.25% (20yr) | $1,857.70 | $145,849 |
| $300,000 at 4.5% (20yr) | $1,897.95 | $155,508 |
| $300,000 at 4.75% (20yr) | $1,938.67 | $165,281 |
| $300,000 at 5% (20yr) | $1,979.87 | $175,168 |
| $300,000 at 5.25% (20yr) | $2,021.53 | $185,168 |
| $300,000 at 5.5% (20yr) | $2,063.66 | $195,279 |
| $300,000 at 5.75% (20yr) | $2,106.25 | $205,500 |
| $300,000 at 6% (20yr) | $2,149.29 | $215,830 |
| $300,000 at 6.25% (20yr) | $2,192.78 | $226,268 |
| $300,000 at 6.5% (20yr) | $2,236.72 | $236,813 |
| $300,000 at 6.75% (20yr) | $2,281.09 | $247,462 |
| $300,000 at 7% (20yr) | $2,325.90 | $258,215 |
| $300,000 at 7.25% (20yr) | $2,371.13 | $269,071 |
| $300,000 at 7.5% (20yr) | $2,416.78 | $280,027 |
| $300,000 at 7.75% (20yr) | $2,462.85 | $291,083 |
| $300,000 at 8% (20yr) ← this page | $2,509.32 | $302,237 |
| $300,000 at 8.5% (20yr) | $2,603.47 | $324,833 |
| $300,000 at 9% (20yr) | $2,699.18 | $347,803 |