Calculators guide
What a $400,000 Home Really Costs Each Month
· 4 min read
A $400,000 home bought with 10% down at 6.5% over 30 years costs about $2,917 a month once property tax, insurance and PMI are added, not the $2,275 that principal and interest alone suggest. Put 20% down and the monthly figure falls to about $2,514, because the loan is smaller and PMI disappears. Adding $200 a month in extra principal to the 10%-down loan pays it off six years early and saves almost $109,000 in interest.
Everything below comes from one scenario run through the Mortgage Calculator. The figures are estimates for planning, not a loan offer or financial advice; your lender, county and insurer set the real numbers.
The scenario
Meet a buyer looking at a $400,000 house. They have $40,000 saved for the down payment, have been quoted 6.5% on a 30-year fixed loan, and want to know what will actually leave their account each month. They use the calculator's default estimates for the extras: property tax of 1.1% of the price per year, home insurance of $1,500 a year, and PMI of 0.5% of the loan per year. No HOA fee.
How does the monthly payment break down?
With $40,000 (10%) down, the loan is $360,000. The calculator splits the first monthly payment like this:
| Part of the payment | Per month |
|---|---|
| Principal & interest | 2,275.44 |
| Property tax | 366.67 |
| Home insurance | 125.00 |
| PMI | 150.00 |
| Monthly payment | 2,917.11 |
Property tax is the price times 1.1%, divided by 12. Insurance is the yearly premium divided by 12. PMI is 0.5% of the $360,000 loan, divided by 12. Only the first line pays down the debt; the other three are costs of owning and insuring the home.
What does 10% down cost compared with 20%?
Our buyer wonders whether to wait and save another $40,000. Running both versions side by side:
| 10% down | 20% down | |
|---|---|---|
| Loan amount | 360,000.00 | 320,000.00 |
| Principal & interest | 2,275.44 | 2,022.62 |
| PMI | 150.00 for 95 months | None |
| Monthly payment | 2,917.11 | 2,514.28 |
| Total interest | 459,160.16 | 408,142.36 |
The bigger down payment lowers the monthly cost by about $403 and total interest by about $51,000. PMI on the smaller down payment runs for 95 months, almost eight years, and adds up to about $14,250 before the balance reaches 80% of the home price and the calculator drops it.
Neither column is "right." Waiting to save more has its own costs, such as rent paid in the meantime and the chance that prices or rates move. The table simply makes the trade-off concrete.
What happens with $200 extra a month?
Our buyer goes ahead with 10% down but plans to add $200 a month to principal. Entering 200 in Extra principal payment changes the picture:
- Time saved by extra payments: 73 months, so the payoff date moves from October 2056 to September 2050 (with a first payment in November 2026).
- Interest saved: 108,916.85.
- PMI now ends after 64 months instead of 95, because the balance reaches the 80% threshold sooner. Total PMI falls to about $9,600.
The headline Monthly payment rises to 3,117.11, since it includes the extra $200. Open the Yearly amortization table and the effect is easy to see: in year one the extra payments raise principal paid from 4,023.81 to 6,496.62, and by year 20 the balance is 102,310.83 instead of 200,395.02.
How to run your own numbers
The Mortgage Calculator updates as you type:
- Enter the Home price.
- Under Down payment as, pick Percent of price or Amount, then fill in Down payment.
- Set the Interest rate and choose a Loan term of 10, 15, 20, 25 or 30 years.
- Replace the estimates for Property tax (percent of price per year), Home insurance (per year) and PMI (if down payment < 20 %) with your own figures, and add any HOA / service charge per month.
- Optionally enter an Extra principal payment and the month of your First payment, which sets the payoff date.
- Read the results, then expand Yearly amortization for principal, interest and balance by year.
The calculation happens in your browser, so your price and savings figures are not sent anywhere. PMI is only charged when the down payment is under 20%. With 20% or more, the PMI line reads "None (down payment is 20 % or more)."
What the estimate leaves out
- Closing costs and lender fees paid upfront.
- Changes over time. Property tax and insurance usually rise; the calculator holds them flat.
- Lender PMI rules. Some loans need a request or an appraisal before PMI is removed, and government-backed loans follow different rules.
- Variable rates. The schedule assumes a fixed rate for the whole term.
To compare loan terms without the housing extras, the Loan Calculator gives a cleaner principal-and-interest view. If the down payment is the hurdle, the Savings Goal Calculator shows how much to set aside each month to reach it.
FAQ
Does my payment drop when PMI ends?
In the calculator's model, yes. The headline monthly payment shows the starting figure including PMI; once PMI stops, that part of the bill goes away while principal, interest, tax and insurance continue.
Why is "Total of loan payments" lower than everything I will pay?
It counts only the loan: the amount borrowed plus total interest. Property tax, insurance, PMI and HOA fees are on top of that figure.
Can I enter my down payment as a dollar amount?
Yes. Switch Down payment as to Amount. Entering $40,000 on a $400,000 home gives exactly the same result as 10%.
Try your own price, rate and down payment in the Mortgage Calculator.