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The Mortgage Calculator Everyone Uses Is LYING to You — It Hides This Cost

By Timothy George · Founder, Infinity Financial Mortgage Corp · 7 min read
A mortgage calculator app on a phone next to paperwork and a small wooden model house on a desk

You punch your numbers into a mortgage calculator, see a comfortable payment, and start house-hunting with confidence. Here's the problem: most of those calculators are quietly leaving out a cost that can add real money to your bill every month. They show you a payment that doesn't exist — and the gap between the fantasy number and reality has surprised a lot of buyers at closing.

The cost they hide: mortgage insurance

The number most calculators show you is just principal and interest — maybe with taxes and insurance. What they routinely skip is mortgage insurance (MI), the extra charge that often applies when you put down less than 20%. Leave it out and the payment looks smaller, but the real one is bigger.

Your real payment is PITI + MI Principal + Interest + property Taxes + homeowners Insurance — that's PITI. If you're putting down less than 20%, add MI on top. A calculator that stops at "P&I" is showing you the trailer, not the movie.
Think of it like an airfare ad ✈️

The big bold price is the base fare. Then come the taxes, the seat fee, the bag fee — and the total at checkout is nothing like the headline. A P&I-only calculator is the bold headline price. Mortgage insurance is one of those fees that doesn't show up until the bill is real. You want the checkout total before you fall in love with a house.

The three loan types handle MI very differently

This is where it gets important, because "mortgage insurance" isn't one thing.

Loan typeHow MI worksWhen it can end
Conventional (PMI)PMI generally applies when you put down under 20%.Can often drop as you reach ~20% equity; lenders generally must remove it automatically at a set point.
FHA (MIP)FHA charges a mortgage insurance premium.With under 10% down, the annual MIP can last the life of the loan — often removed only by refinancing.
VANo monthly mortgage insurance for eligible borrowers.N/A (a one-time funding fee may apply instead).

Conventional: PMI can be temporary

On a conventional loan, PMI is often the easiest to shed. As you pay down the balance and build equity — commonly around 20% — you can typically request cancellation, and under federal rules lenders generally must remove it automatically once you hit a set threshold. That makes "put less than 20% down now, drop PMI later" a real strategy for many buyers.

FHA: the trap people miss

FHA is different, and this is the part that catches people. If you put down less than 10%, the annual MIP can stick around for the life of the loan. Building equity alone may not remove it — often the only exit is refinancing into a different loan entirely. That doesn't make FHA bad; it makes it a cost you need to see clearly before you choose it.

VA: no monthly MI

For eligible borrowers, VA loans generally carry no monthly mortgage insurance at all — a meaningful advantage. There can be a one-time funding fee, but the absence of a recurring MI line can make the true monthly payment noticeably friendlier.

Use a calculator that tells the truth

The fix is simple: use a calculator that breaks out MI as its own line so you see the real PITI + MI total — not a flattering P&I-only number. Our Mortgage Payment + MI calculator is built to show that line, so the payment on the screen is the payment you'd actually budget for.

Questions to ask before you commit

Want the real payment, MI and all?

Grab the free Stuck Homeowner's Playbook and run your scenario with a calculator that shows mortgage insurance as its own line.

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Frequently asked questions

What is PMI and why do I pay it?
PMI is private mortgage insurance on conventional loans. It generally applies when you put down less than 20% and protects the lender, not you, if the loan defaults. It's typically added to your monthly payment.
When does PMI go away?
On a conventional loan, PMI can often be cancelled as you build equity, commonly around 20%, and lenders generally must remove it automatically at a set point under federal rules. Specific timing depends on your loan and servicer.
Does FHA mortgage insurance ever go away?
It depends on your down payment. On many FHA loans with less than 10% down, the annual MIP can last the life of the loan, and removing it often means refinancing. With 10% or more down, it may drop off after a set number of years.
How much is mortgage insurance?
It varies by loan type, down payment, and credit profile, and is usually a percentage of the loan paid annually and split into monthly amounts. Because it changes case by case, use a calculator that shows MI as its own line.

Related free tools: Mortgage Payment + MI calculator · down payment comparison

Educational content only — not financial, mortgage, or legal advice, and not a loan offer or solicitation. Timothy George is the founder of Infinity Financial Mortgage Corporation with 20+ years in mortgage and auto finance; this is independent educational material and he is not acting as a currently-licensed loan originator. Mortgage insurance rules, rates, and cancellation terms vary by loan type and program — confirm specifics with a currently-licensed professional before you act.