The payment is not the loan
Ask what a mortgage costs and most calculators answer with principal and interest. That is the payment on the debt, and for a great many buyers it is well short of what actually leaves the account. Property tax, home insurance, any association fee and, on a thin deposit, mortgage insurance are all part of the bill, and all four are usually collected by the lender alongside the loan payment rather than sent separately.
This page adds them up. The headline figure is the first month in full, and the bar underneath splits it so you can see how much of it is repaying anything at all. On a new thirty-year loan the answer is sobering: the slice that reduces the balance is the smallest one on the bar.
Why we do not fill in your property tax
The interest rate on this page arrives filled in, from a weekly survey published under a government charter, with the week it describes printed underneath. Property tax and home insurance do not, and that is a deliberate gap rather than an oversight.
Property tax is set county by county, sometimes district by district within a county. The Census Bureau does publish median real estate taxes paid down to county level, which is the right source and the one we would use, but its bulk files and its data API are both closed to automated access without a registered key, so we do not have it yet. Home insurance has no equivalent source at all: premiums are priced property by property, and a national average would be wrong for almost everybody who read it. Filling either field with a plausible-looking number and attaching a source label to it would be the one kind of error worth avoiding above all others, so both fields start empty and wait for the figure on your own bill.
Mortgage insurance ends on a date, and it is not the date you expect
Put down less than a fifth of the price on a conventional loan and the lender will require mortgage insurance. It protects the lender, not you, and it comes off eventually. When it comes off is governed by statute, and the statute contains a trap that almost every calculator gets wrong.
Automatic termination happens when the balance reaches seventy-eight per cent of the original price on the schedule the loan started with. The law says this explicitly: it applies irrespective of what the balance actually is on that date. Pay an extra amount every month for five years and you will be well under the threshold long before the date arrives, and the insurance will keep being charged anyway.
What paying extra does move is the other date. Once the real balance reaches eighty per cent you may ask to have the insurance cancelled, subject to being up to date on payments, having no second lien and the property not having lost value. That request has to be made; nothing happens on its own. When both dates apply to your loan, the page shows both and says which is which. There is also a backstop: the insurance may not be charged past the midpoint of the loan term whatever the balance has done, which is the rule that binds on a high rate with a very small deposit.