// pre-computed reference
15-year mortgage at 8.0%: total interest by loan amount
Exact principal-and-interest figures for a fixed-rate 15-year mortgage at
8.0%, computed with the standard amortization formula. For your own numbers, use the
interactive calculator.
| Loan amount | Monthly P&I | Total interest |
Total paid | Interest % of loan |
|---|
| $100,000 | $956 | $72,018 | $172,018 | 72% |
| $200,000 | $1,911 | $144,035 | $344,035 | 72% |
| $300,000 | $2,867 | $216,051 | $516,051 | 72% |
| $400,000 | $3,823 | $288,069 | $688,069 | 72% |
| $500,000 | $4,778 | $360,087 | $860,087 | 72% |
At 8.0% over 15 years, every dollar borrowed costs about
72 cents in interest. A 15-year term reaches the principal-over-interest crossover early, which is why its totals run far below a 30-year loan at the same rate.
See the term comparison or the
extra payment calculator to shrink these numbers.
15-year at other rates: 4.0% · 4.5% · 5.0% · 5.5% · 6.0% · 6.5% · 7.0% · 7.5%
8.0% at other terms: 10-year · 20-year · 25-year · 30-year
Frequently asked questions
How much interest on a $400,000 mortgage at 8.0% for 15 years?
Total interest is about $288,069, with a monthly principal-and-interest payment of $3,823. That's 72% of the amount borrowed, before taxes and insurance.
Is 8.0% a good rate for a 15-year mortgage?
Rates move with the market and your credit profile; compare current quotes from several lenders. Whatever your rate, the table above shows what it costs in total interest.
How can I pay less than $288,069 in interest?
Pay extra toward principal, choose a shorter term, or refinance if rates drop. Use the extra payment calculator to see your exact savings.
How is the 15-year payment at 8.0% calculated?
With the standard amortization formula — P·r(1+r)ⁿ/((1+r)ⁿ−1) — over 180 monthly payments, computed to the cent. The full formula and rounding rules are on our methodology page.