Calculate principal, interest, tax, and insurance. See exactly what you owe each month.
| Month | Payment | Principal | Interest | Balance |
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Four inputs decide the payment, and one of them is the number people most often get wrong.
A 20% down payment on a $356,250 house is $71,250, leaving a $285,000 loan. At 6.75% for 30 years the principal and interest payment is $1,848.50. Across 360 payments you hand over $665,462, of which $380,462 is interest, more than the amount borrowed.
Add the escrow lines. Property tax of $4,800 a year is $400 a month and insurance of $1,500 a year is $125, so the real monthly housing payment is $2,373.50 before any HOA dues or mortgage insurance.
The same $285,000 at 6.25% for 15 years is $2,443.66 a month, about $595 more every month, and the total interest falls to $154,858. Over the life of the loan the shorter term saves roughly $225,604. That is the trade in one line: a payment increase smaller than a car payment, against a quarter of a million dollars of interest. Whether it is affordable is a separate question from whether it is cheaper, and the payment-to-income answer lives on the affordability calculator.
Principal and interest is the loan. Tax and insurance is the escrow. Lenders quote both together as PITI, and buyers who budget only the first number are the ones surprised at closing.
Early payments are mostly interest because interest is charged on the remaining balance, and the balance is at its highest in month one. On this loan the first payment is roughly $1,603 of interest and $245 of principal. That asymmetry is why an extra principal payment in year one is worth far more than the same payment in year twenty, and why the first-year table is worth reading before you sign.
Three costs this page does not include: private mortgage insurance, which usually appears on a conventional loan below 20% down and is quoted by the lender; HOA dues, which can be a second mortgage payment in some buildings; and closing costs, which are paid at the table rather than monthly.
Use the mortgage payment to compare two specific quotes on one house, then take the price back to the affordability question. Decide what you can afford first, then optimize the loan. Doing it in the other order is how people end up house-poor in a house they can technically finance.
The rate. APR includes lender fees and points spread over the loan, which makes it useful for comparing offers and useless for computing a monthly payment. Use the note rate in the calculator and the APR when you compare two Loan Estimates.
Tax and insurance, yes, if you enter the yearly amounts. PMI is not included. If your down payment is under 20% on a conventional loan, ask the lender for the monthly mortgage insurance figure and add it yourself.
Interest is a percentage of the outstanding balance, and the balance is at its peak in month one. As principal is repaid the balance falls, the interest share shrinks, and later payments shift toward principal.
On a $285,000 loan at 6.25% versus 6.75%, about $225,604 of interest, in exchange for roughly $595 more per month. Run your own rate and amount, because the gap depends heavily on the rate difference between the two products.
This table shows the scheduled payment only. An extra principal payment shortens the term and cuts interest, and the loan calculator models extra payments directly if you want to see the effect.
It is cheaper in total interest but it is not free. A higher required payment is a risk if income drops, and the difference is only worth it if the payment stays comfortable in a bad year, not just a good one.
The payment is the ordinary fixed-rate amortization formula. The consumer rules around it are the CFPB's.
Last updated: November 2, 2026. Reviewed by David Liu. Fixed-rate, fully amortizing loans only. Adjustable rates, interest-only terms, and biweekly programs are not modeled.