The full payment is the only number that matters
Ask five people what their mortgage payment is and you will get five different definitions. Some mean just principal and interest. Some include taxes and insurance. Almost nobody includes HOA dues until the bill shows up. Your lender qualifies you on the full number, so that is the only one worth planning around.
This calculator adds all four pieces together on purpose. If a number online looks lower than what I quote you, it is almost always because it left something out, not because the deal is better.
Property tax moves the number more than people expect
In Central Texas, property tax rates vary a real amount between Hays, Travis, and Caldwell counties, and between school districts inside them. Two identical houses a few miles apart can carry noticeably different monthly tax bills.
The default rate here is a placeholder built to be in the right neighborhood, not the rate on your specific address. I pull the actual rate for a property before you write an offer, because it is one of the few numbers in this whole process that is not negotiable.
Mortgage insurance is not in this number yet
If your down payment is under 20 percent, most loan types add mortgage insurance on top of what this calculator shows. How much depends on your loan type, your credit, and your down payment, which is exactly the kind of thing worth a real conversation instead of a guess.
On a conventional loan it falls off once you reach enough equity. On FHA it usually does not. That difference alone changes which program is the better long-run choice for some buyers.
A rate you type in is not a rate you are offered
The rate field here is yours to move. It is not pulled from a live feed, and it is not a quote. That is intentional. Real pricing depends on your credit, your loan type, your property, and the day you lock, and I am not going to put a number in front of you that implies otherwise.
What this tool is good for is seeing how sensitive your payment is to rate, and to down payment, before you are sitting across from a purchase contract with a deadline attached to it.