A $400,000
home with 20%
$80,000 down, $320,000 borrowed. down, at 6.71%
for 30 years
$400,000
20%
$80,000 down, $320,000 borrowed.6.71%
30 years
with 1.1%
$367/mo — $4,400 a year on this home.0.35%
$117/mo — $1,400 a year on this home.$0.00
A $320,000 mortgage at 6.71% over 30 years is $2,067/mo in principal & interest — $2,550/mo with property tax and insurance — and $424,125 in total interest over 30 yr. Change any figure above to see your monthly payment, principal-vs-interest split, balance paydown, and how extra payments shorten the loan.
Seeded with the 30-year fixed average of 6.71% — Freddie Mac's weekly survey for the week of Sep 3, 2026. See rates back to 1971 →
Monthly payment breakdown— first payment
- Principal$278/mo11%
- Interest$1,789/mo70%
- Tax$367/mo14%
- Insurance$117/mo5%
Principal vs interest shown for the first payment — the principal share grows every month.
Where your money goes— over the whole loan
- Principal$320,00043%
- Interest$424,12557%
Payment composition by year— equity built vs money gone for good
Each month: equity built vs money gone— principal vs interest + tax + insurance
"Gone for good" = interest + property tax + insurance — money that never comes back. Equity/mo is the principal you pay off; it rises every month as the balance shrinks, and from month 275 your payment builds more than it burns.
Loan balance over time— remaining principal
Amortization schedule, by year
| Year | Principal paid | Interest paid | Balance |
|---|---|---|---|
| 1 | $3,437 | $21,368 | $316,563 |
| 2 | $3,674 | $21,130 | $312,889 |
| 3 | $3,929 | $20,875 | $308,960 |
| 4 | $4,201 | $20,604 | $304,760 |
| 5 | $4,491 | $20,313 | $300,269 |
| 6 | $4,802 | $20,002 | $295,467 |
| 7 | $5,134 | $19,670 | $290,332 |
| 8 | $5,490 | $19,315 | $284,843 |
| 9 | $5,870 | $18,935 | $278,973 |
| 10 | $6,276 | $18,528 | $272,697 |
| 11 | $6,710 | $18,094 | $265,987 |
| 12 | $7,174 | $17,630 | $258,813 |
| 13 | $7,671 | $17,133 | $251,142 |
| 14 | $8,202 | $16,602 | $242,940 |
| 15 | $8,769 | $16,035 | $234,171 |
| 16 | $9,376 | $15,428 | $224,795 |
| 17 | $10,025 | $14,779 | $214,770 |
| 18 | $10,719 | $14,085 | $204,051 |
| 19 | $11,461 | $13,344 | $192,591 |
| 20 | $12,254 | $12,551 | $180,337 |
| 21 | $13,102 | $11,703 | $167,236 |
| 22 | $14,008 | $10,796 | $153,227 |
| 23 | $14,978 | $9,826 | $138,250 |
| 24 | $16,014 | $8,790 | $122,235 |
| 25 | $17,122 | $7,682 | $105,113 |
| 26 | $18,307 | $6,497 | $86,806 |
| 27 | $19,574 | $5,230 | $67,232 |
| 28 | $20,929 | $3,875 | $46,303 |
| 29 | $22,377 | $2,427 | $23,926 |
| 30 | $23,926 | $878 | $0.00 |
Methodology
Payments use the standard fixed-rate formula and assume a constant interest rate for the life of the loan. Property tax and homeowners insurance are estimated as an annual percentage of the home's value (US averages: ~1.1% tax, ~0.35% insurance) and added to the monthly payment as escrow — they don't affect the loan amortization. PMI and HOA dues are not included and vary by lender and location. "Extra / month" is applied to principal each month, which shortens the term and cuts total interest; the schedule is aggregated by year. Figures are estimates for planning, not a loan offer or financial advice.
FAQ#
- How is a monthly mortgage payment calculated?
- It uses the standard fixed-rate amortization formula — a level monthly principal-and-interest payment over the full term. For example, a $320,000 loan at 6.71% over 30 years works out to $2,067/month in principal and interest.
- What's included in the monthly payment?
- Principal and interest on the loan, plus optional escrow for property tax and homeowners insurance (estimated as a percentage of the home's value). PMI and HOA dues are not included — they vary by lender and location.
- How do extra payments save money?
- Any amount you add toward principal each month is applied directly to the loan balance, which shortens the term and cuts total interest. Set an extra-payment amount above to see exactly how many months and how much interest you'd save.
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